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Section 1, Disassembly and Assembly ........................ 13 

Section 2, How the Carbine Functions 24 

Section 3, Operation 30 

Section 4, Immediate Action and Stoppages 32 

Section 5, Care and Cleaning 32 

Table I: Stoppages and Malfunctions 33 

Section 6, Spare Parts, Appendages and Accessories 39 

Section 7, Ammunition 40 


Section 1, General 43 

Section 2, Technical Inspection 44 

Table II: Inspection Guide 45 

Table III, Trouble Shooting 62 


Section 1, General ,; * 55 

Section 2, Rebuild Flow Chart ;,...... 58 

Table IV: Operations Route Sheet 59 

Section 3, Trigger Housing Group, Carbines Ml, Ml Al 62 

Section 4, Trigger Housing Group, Carbines M2, M3 . , ... 67 

Section 5, Operating Slide Assembly 69 

Section 6, Bolt Group 72 

Section 7, Front Sight Assembly ... ... 73 

Section 8, Rear Sight Assembly 75 

Section 9, Barrel and Receiver Group 79 

Section 10, Stock Group, Carbines Ml, M2, M3 90 

Section 11, Stock Group, Carbine M1A1 . 94 

Section 12, Magazine Assembly 98 


Addendum, Targeting Requirements «... 102 


I. Historical Background 

Although the term carbine is almost as old 
as shoulder weapons themselves, the concept of 
a military weapon designed from the start as a 
carbine is uniquely Twentieth Century, as are the 
airplane, submarine, missile-armed satellites and 
neutron bombs. 

One of the earliest references to the term 
carbine and its possible origin appeared in 1548. 
According to that source, the word derived from 
the short barreled rifles carried by Spanish cavalry 
groups which were then called "Carabins'*, If this 
is true, the term would be appropriate since the 
carbine has, until just recently, been uniquely a 
cavalry weapon . While there has been a trend 
toward shorter barrels on military rifles for the last 
century and a half or so, the practice of issuing 
rifles with barrels as long as 30" was quite common 
even up through World War L The M1903A3 
Springfield, for example, had the shortest barrel of 
any standard issue shoulder arm during that 
conflict. Its 24" tube may be long by today's 
standards, but it was considerably shorter than the 
M1891 Mo&in-Nagant's 31.6'* or the French Lebel 
M1886's 31.4". Although called a rifle, the M1886 
M93R35 was a true carbine with its 17.7" barrel 
However, we can't help but wonder just how 
effective it was in combat, since it had only a three 
round magazine. 

While it is obvious that every war since the 
invention of the written language has brought its 
technological advances, the two World Wars 
probably brought about more changes for the 
actual length of time of the conficts than any 
other wars. Part of the reason for this, of course, 
is the capabilities for rapid change made possible 
by the Industrial Revolution. 

The internal combustion engine made air- 
planes for observation, and later for bombing, 
a reality, as well as tanks and motorized transport. 
Crude, man-powered submarines had been used 
as early as the Revolutionary War, but when war 
raced across Europe in the summer of 1914, 
powered submarines were already in service. 
Although mule transport and horse cavalry lasted 
on into World War II, mechanization had definitely 
sounded their death knell. 


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Stock Ml Carbine as manufactured by Winchester, 
Inland, Rock Ola, etc. 

Almost from its inception, the pistol had been 
considered a last ditch weapon for cavalry, the 
primary weapons being the carbine and saber. 
This practice was still prevalent during the Indian 
Wars in this country and in the Middle East during 
World War 1. But as horse cavalry vanished into 
the dim mists of the past, so did the saber. Mech- 
anized cavalry were armed with pistols and T in 
some cases, submachine guns. While some SMGs 


had found their way into the trenches near the end 
of the "War To End All Wars", they weren't to 
become prevalent in warfare until the Spanish 
Civil War, when their effectiveness in close quarters 
fighting was firmly established. 

Interestingly enough, the United States began 
looking for a weapon to replace the SMG even 
before it was used in any quantity by U.S. troops. 


M2 Carbine with folding stock. 

As early as 1938, the U.S. Army began 
thinking about a light rifle or carbine as a re- 
placement for both the Colt N1911A1 and the 
Thompson SMG. While the recently adopted Ml 
Garand rifle was far and away the finest battle 
rifle in the world at that time, it was too heavy 
and bulky to be used by support troops who would 
normally not see combat but who were armed 
"just in case". Previous practice had been to arm 
such personnel with the Colt .45, a superior 
weapon for close in work but definitely not a good 
choice for the average shooter at medium to long 
ranges. In the late 1930's, the U.S. armed forces 
had only a limited number of Thompsons in their 
inventories, so replacing them would hardly prove 
an awesome burden. As for the Colt .45, well — it 
had been in service for nearly thirty years, so was 
undoubtedly obsolete, as military thinking at that 
time was beginning to view the military pistol in 
any form as a relic of the past. 

The initial concept of the new light rifle or 
carbine was for it to weigh five pounds or less, 
complete with sling, and have an effective range 
of 300 yards, tt should be semi-auto with capa- 
bility for full automatic fire, have little noticeable 
recoil and be chambered for a cartridge similar to 

Winchester's .32 centerfire which they had de- 
veloped for their Model 1905 autoloading rifle. 

In the fall of 1940 the Ordnance Department 
approached Winchester with their specifications 
for the new cartridge. Following development 
work, an order for 150,000 rounds was placed in 

June of the following year. A second order for 
300,000 rounds followed in August. 

Winchester was also invited to submit a 
prototype weapon for testing, but they were 
deeply involved in Garand production and de- 
clined. When trials began on June 16, John Garand 
himself had submitted two designs. Others sub- 
mitting prototypes included Auto Ordnance 
(manufacturer of the Thompson), Harrington & 
Richardson, Hyde, Savage, Springfield Armory and 
Woodhull. Two weeks later, Winchester was 
again invited to submit a test sample, and agreed. 
A mere two weeks later to the day, a very quickly 
hand assembled sample was submitted to Ord- 
nance. While not a true indication of what the 
production gun would be like, this crudely as- 
sembled sample worked so well that Ordnance 
felt it offered far more promise than any of the 
other guns previously tested. The Winchester 
team went back to work at the drawing board and 
assembly bench and, after 34 days of working 
literally day and night, had a finished carbine 
ready for the September tests at Aberdeen Proving 
Ground. At the end of the testing period, the 
board unanimously recommended adoption of the 
Winchester design. Less than two weeks before the 
attack on Pearl Harbor, an order for 350,000 
Ml Carbines was placed with Winchester. 

The slide, bolt, sear, magazine catch and trigger 
housing shown above are necessary for converting 
the M1 to M2 configuration, but are not con- 
sidered part of the conversion kit. Not shown, 
and also necessary for the conversion, is the M2 

Tooling up for large scale production is a 
different story than creating a prototype, however, 
and the first carbines didn't come off the Win- 
chester production line until almost three weeks 


after the U.S, Marines had landed on Guadalcanal 
in August 1942. That particular lot consisted of 

just 10 carbines. 

In order to facilitate speedy delivery of the 
much-needed carbines as American troops were 
shipped off to North Africa and the Pacific, 
production contracts were also awarded to the 
Inland Manufacturing Division of General Motors f 
Underwood Elliott Fisher, National Postal Meter, 
Rock-Ola Manufacturing Corp., Quality Hardware, 
Standard Products, Saginaw and IBM. Even though 
Winchester was the only carbine producer that was 
normally a firearm manufacturer, by the end of 
1943 Mis were rolling off the production line at 
the rate of 500,000 per month. 

As the tides of war began to turn in favor of 
the Allies^ it became apparent that a select fire 
carbine as called for in the original specifications 
was highly desirable, especially in the jungle where 
the distances at which confrontations occurred 
could often be measured in feet rather than yards 
and where the enemy might be visible for only a 
few seconds, if at all. Some non-military minds in 
Washington had trouble distinguishing the concept 

of burst fire from that of sustained fixe associated 
with belt-feds. However, requests for a select fire 
carbine kept coming in from the field commanders 
who had to stand and watch their men die due to 
the lack of adequate firepower. 

It is highly unusual for a selective fire weapon 
to be developed from a semi-auto only design > 
but in the case of the M2 Carbine that is exactly 
what happened. The end result was actually 
two different types of M2 Carbines — the "pure" 
version which was manufactured as a selective 
fire weapon from the ground up, and the "hybrid" 
which had gone into service as a standard semi- 
auto Ml, then been converted to M2 configuration 
by installing a T17 kit. This kit was designed so 
that existing Mis could be converted to select fire 
without being sent back to an arsenal for "major 

M2 Carbines went into production at the 
Winchester and Inland plants in May 1945, the 
same month that Germany surrendered. With 
the surrender of Japan the following September, 
the world supposedly returned to a state of peace, 
and production of the Ml and M2 Carbines ended. 


Experimental & Prototype 
















TOTAL 836,680 

Inland Manufacturing Division 
of General Motors Corporation 


140 r 591 
199 r 500 



TOTAL 2,626,807 

Underwood- E 1 1 iott- F ish er 
Ml 546,616 

Rock-Ola Company 

Ml 228,500 

Quality Hardware & Machine Corp. 





National Postal Meter 

412 r 778 

Commercial Controls Corp. 


Irwin-Pederson Arms Company 
M1 146,723 

Standard Products Company 

M1 346,225 

Saginaw Steering Gear Division 

of General Motors Corporation 

M1 370,490 

International Business Machines Corp. 
Ml 346,500 

TOTAL 2,757,733 



Inland 1 to 5 

Winchester 6 to 10 

Inland 11 to 999,999 

Winchester 1,000 r 000 to 1,249,999 

Underwood 1,250,000 to 1,449,999 

National Postal Meter 1,450,000 to 1,549,999 

Quality Hardware & Machine 1,550,000 to 1,562,519 

Quality Hardware & Machine 1,562,520 to 1,662,519 

Rock-Ola 1,662,520 to 1,762,519 

IRWIN PEDERSEN (Saginaw, G.R.J 1,762,529 to 1,875,039 

Quality Hardware & Machine 1,875,040 to 1,907,519 

Quality Hardware & Machine 1,907,520 to 1,937,519 

National Postal Meter 1,937,520 to 1,982,519 

Standard Products 1.982,520 to 2,352,519 

Underwood 2,352,520 to 2,912,519 

Inland 2,912,520 to 3,212,519 

Irwin Pedersen [Saginaw, G.R.J 3,212,520 to 3,250,019 

Saginaw S.G. 3,250,020 to 3,651,519 

1.B.M 3,651,520 to 4,009,999 

Underwood 4,010,000 to 4,074,999 

National Postal Meter 4,075,000 to 4,079,999 

National Postal Meter 4,080,000 to 4,432,099 

Quality Hardware & Machine 4,432,100 to 4,532,099 

Rock-Ota 4,532,1 00 to 4,632,099 

Quality Hardware & Machine 4,632,100 to 4,879,525 

Inland 4,879,526 to 5,549,821 

Winchester 5,549,822 to5,834,618 

Saginaw S.G 5,834,619 to 6,071,188 

Rock-Ola 6,071,189 to 6,099,688 

Underwood 6,099,689 to 6,199,688 

Rock-Ola 6,199,689 to 6,219,688 

Inland 6,219,689 to 6,449,867 

Winchester 6,449,868 to 6,629,883 

Inland 6,629,884 to 7,234,883 

Winchester 7,234,884 to 7,369,660 

Inland 7,369,661 to 8,069,660 

Commercial Controls Corp 0001 to 0239 

* The reader may note that the assigned serial numbers above add up to approxi- 
mately 2 million more carbines than the 6 million total production discussed in 
the text. This Is not a typographical error, but is the result of spare numbers being 
assigned within blocks of numbers, some receivers being scrapped after being 
stamped and their numbers being re-used at a later date, etc. Additionally, major 
design changes or improvements were often designated by starting with a new block 
of numbers and purposely leaving a gap between the numbers of the first gun of the 
new model and the last one of the old. 


A total of over 6 t 000,000 of both models was 
produced before VJ Day- 
Less than five years after the Japanese sur- 
render in Tokyo Bay, war clouds again loomed 
over Japan when North Korean troops moved 
south in June of I960. One need only study a map 
of the Far East to realize the trepidation that must 
have filled the minds of American occupation 
troops in Japan at the outbreak of the Korean War, 
Within weeks, mothballed fighter aircraft, landing 
craft, Garands and Ml and M2 Carbines were 
being refurbished to go to war. For three years the 
Ml Carbine was to serve American troops in the 
frozen wastes of Korea, and names like Pork Chop 
Hill, Inchon and the Yalu River had become as 
familiar to the American people as Omaha Beach, 
El Alamein and Iwo Jima. With the signing of an 
uneasy truce in July 1953, the Mis and M2s were 
once more put back into storage. 

Only a year later, an event took place that 
was to signal the Mi's return to the front lines 
for yet another war. A French Indochinese fort by 
the name of Dien Bien Phu fell to Communist 
forces in far off Southeast Asia. However, it 
doesn't seem so far away today when you think of 
the present name for the country in which Dien 
Bien Phu is located — Vietnam. 

With the end of the 300 year French rule in 
Indochina, the peninsula was divided into three 
countries, the largest being Vietnam. One might 
have thought the French withdrawal would bring 
peace to Southeast Asia, but such was not the 
case. Fighting continued between Communist 
regulars and guerrillas and the forces of the demo- 
cratic governments of the countries that had been 
French Indochina. The situation had deteriorated 
so badly by the early 1960*s that American "ad- 
visors" were sent to help the South Vietnamese. 
What followed was history, with American troops 
eventually becoming involved in the longest war 
in which America ever fought. By the time the 
Vietnam War officially ended in the early 1970 T s, 
over 50,000 American servicemen had payed the 
ultimate price for freedom. 

Although some Ml Carbines saw service 
with American troops in Vietnam, by far the 
greatest users of the Ml were the Vietnamese 
themselves. Due to their smaller physical stature, 
they liked the small, light carbine with the neg- 
ligible recoil The Ml Garand had, of course, 
been replaced by the M14 as the standard service 
rifle. Although the 7.62mm NATO cartridge of the 
M14 produced less recoil than the Garand *s .30-06, 
it was still a bit much for the Vietnamese* They 

made do with Ml Carbines until the ArmaUte 
AR-15 became available in quantity. It was largely 
upon their recommendation that Gen. William 
Westmoreland requested AR-15s for the American 
troops which were dissatisfied with the M14 *s 
performance in the tropics. It should be pointed 
out, however, that the AR-15 which had endeared 
itself to the Vietnamese was a select fire weapon 
that was the forerunner of the M16, and not 
the semi-auto only civilian AR-1 5 we know today. 




• V"- 

Although once readily available at gun shows. 
the M2 parts shown above are available as a group 
now only through Class III dealers since the 

complete kit is classified as a machine gun, even in 

the absence of the carbine itself. 

Although the Ml and M2 Carbines are no 
longer standard issue with any American military 
unit, a number of them are still in government 
storage for possible future use. As of Spring 
1984, 65,984 Ml and 7,298 M2 Carbines were 
being held for special contingency and foreign 
military sales requirements. Ml Carbines are 
likely to be encountered just about anywhere in 
the world, either in the hands of guerrillas or 
small local militia units fighting against them. 
While the Ml failed to replace either the Colt 
M1911 Al or the SMG, both of which are still on 
active duty with U.S. forces, it served its country 
and her allies well in war and is now a favorite 
"pickup" gun of ranchers and farmers who want a 
small, lightweight arm with minimal recoil that is 
still more powerful than a .22 rimfire. Just how 
many surplus Ml Carbines have found their way 
into civilian hands is anyone's guess, but the fact 
that Ruger chambered its popular Blackhawk single 
action revolver for the .30 Carbine cartridge attests 
to the round's popularity. 

Numerous commercial models of the Ml 
have been produced by various manufacturers since 
World War II and Iver Johnson currently offers a 


select fire version for police and foreign markets as a gun show or brand net? out of the box from the 

well as the "standard" version for the U.S. civilian local gun shop, the Ml Carbine should be with us 

market. Whether as a surplus weapon picked up at for a long time to come. 

II. Description & Data 


The carbines are gas-operated, self-loading, 
air-cooled shoulder weapons, fed by 15-round 
or 30-round cartridge magazines. The carbines Ml 
and M1A1 deliver semi-automatic fire, and the 
carbines M2 and M3 deliver either semi-automatic 
or full automatic fire controlled by the operator 
through the use of a selector. 


a. Tactical Inspection. For information on 
differences between models which affect troop 

use, refer to page 44. 

b. Cat. .30 Carbines Ml and M1A1 (Figs. 1 
and 2). The only difference between the carbines 
Ml and M1A1 is the stock. The Ml has a one- 
piece wooden stock, whereas the M1A1 has a 
folding metal stock extension and a wooden hand 


c. CaL .30 Carbines M2 and MB (Figs. 3 
and 3a). The carbine M2 is the same as the Ml 
except for differences in design of certain com- 
ponents and the addition of others (d below), 
which permit the M2 to deliver either semi-auto- 
matic or full automatic fire. The carbine M3 is the 
same as the M2 except that the rear sight is not 
included and the top of the receiver is designed to 
accomodate special sighting equipment (sniper- 
scope) issued by the Corps of Engineers. Infor- 
mation on the sniperscope may be found in TM 


d. Component Differences Between Full 

Automatic and Semi-Automatic Carbines (Fig. 3b). 
Note. The hammer, sear, trigger housing, 
operating slide, and stock of the carbine M2 

■a fp n*m 

Figure 1. Cal. .30 carbine Ml. 

(described in (1) through (5) below) can also be 
used on the carbine Ml. 

(1) Hammer. The hammer of the carbine 
M2 is the same as the hammer of the 
Ml carbine, except that it has a milled 

■i. _ 

f M 

im not vww 



to fp ei«(M 

■ . .. ■ ■ ■,.,' 

Figure 2. Cal. .30 carbine M1A1. 


■^'■■■■: : .v^- ; i-;;;^,. :: ;;.^; :■::.:. 

.; ■:■'.'■■ .,■-■■: : 

.,- m-m ■-■y.- . ■■'■ 

-sSH8b§-' ,, ''' , . ,, ''' : ■■■. 


Figure 3. Cal, .30 carbine M2. 


cut in the lower right aide to furnish 
clearance for the disconnector when 
assembled on the hammer pin (Fig. 
(2) Sear. The sear (Fig. 52) of the carbine 
M2 is the same as the sear of the 
carbine Ml, except for a raised shoul- 
der on the top of the front end, which 
forms a camming surface for the 
disconnector when operated. 

Trigger housing. The trigger housing 
of the carbine M2 is the same as that 
of the carbine Ml, except that the left 
side of the magazine post is furnish- 
ed with a retention slot, and the front 
face of the post with a dismounting 
notch for the selector spring. (The 
dismounting notch leads into the top 
of the slot.) The right side has a milled 
cut for clearance of the disconnector 
lever. The left side has a milled cut for 
the selector. 

Operating slide. The operating slide 
(Fig. 58) of the carbine M2 is the same 
as that of the carbine Ml, except for 
a clearance cut extending along the 
right-hand side of the body, and a 


diagonal cut at the point where the 
shank of the handle joins the body. 
The latter cut forms a cam for camming 
down the forward end of the dis- 
connector lever. 

(5) Stock (Fig. 99). A clearance cut is made 
in the inner right wall of the M2 
carbine to provide clearance for the 
projecting right side of the discon- 
nector. A cut is also made in the inner 
left wall for clearance for the selector. 
The bridge is cut down to the central 
section for clearance for the discon- 
nector lever. 

(6) Disconnector group — added parts 
(Fig. 56). The disconnector pivots on 
the hammer pin when assembled. 
The rear end has a lateral projection, 
which bears upon the raised shoulder 
of the sear, when the disconnector is 
cam-operated by the disconnector lever 
for full automatic fire. The forward 
end has a projecting lug on the right 
side, which extends outside the trigger 
housing and engages and acts as a 
camming surface for the rear end of 
the disconnector lever. A spring and a 




Weight of carbines Ml, M2 and M3 (without sniperscope) 

with 15-round magazine (unloaded) 5.50 lb. 

Weight of carbine MIA 1, with 15-round 

magazine (unloaded) 6.19 lb. 

Weight of carbines Ml, M2 and M3 (without sniperscope} 

with 15-round magazine (loaded] and sling 6.10 lb. 

Weight of carbine M1A1 with 15-round 
magazine (loaded) and sling 6.79 lb. 

Weight of carbines M2 and M3 (without sniper- 
scope) with 30-round magazine (untoaded) 5.53 lb. 

Weight of carbines M2 and M3 (without sniper- 
scope) with 30-round magazine (loaded) 6.60 lb. 

Magazine capacity (old type} 15 rd . 

Magazine capacity (new type) 30 rd. 

Weight of 15-round magazine (unloaded) 0-17 lb. 

Weight of 15-round magazine (loaded) 0.59 lb. 

Weight of 30-round magazine (unloaded) 0.23 lb. 

Weight of 30-round magazine (loaded) 1 .07 lb. 

Over-all length of carbines Ml, M2 and M3 35.58 in. 

Over- all length of carbine M1A1 
(stock extension extended) 35.63 in. 

Over-all length of carbine M1A1 
(stock extension folded) 25.51 in. 

Over-all length of carbines Ml, M2 and M3 
with bayonet attached 42.26 in. 

Over-all length of carbine M1A1 with bayonet 
attached (stock extended) 41.31 in. 

Weight of 100 cartridges 2.8 lb. 

Weight of 1 ball cartridge 1 93 gr. 

Weight of bullet (approx.) 11 1 gr. 

Muzzle velocity 1,900-2,000 f.p.s. 

Pressure in chamber per square inch 
maximum (approx.) 40,000 lb. 

Maximum range 2,000 yd. 

Effective range 300 yd. 

Rate of fire, full automatic (M2 and M3) 750-775 r.p.m. 

Length of barrel 18.00 in. 

Sight radius at 100 yards 21.5 in. 

Trigger pull 4 1 /a-7 lb. 

Shipping weight of nailed wood box containing 

10 carbines Ml, M2or M3 (without sniperscope) 98 !b. 

Shipping weight of nailed wood box 

containing 10 carbines M1 A1 90 lb. 

Dimensions {outside) of nailed wood box containing 

10 carbines Ml, M2 or M3 (without sniperscope) 40^x17x11% 

Dimensions (outside) of nailed wood box 

containing 10 carbines (M1A1 30%x19%x10% 

[Continued on following page] 


Cubical displacement of nailed wood box containing 

10 carbines Ml, M2 or M3 (without sniperscope) 4.7 cu. ft. 

Cubical displacement of nailed wood box 

containing 10 carbines M1A1 3.5 cu. ft. 


As originally manufactured, the Ml and 
M1A1 .30 Carbinas were built to deliver semi- 
automatic fire. The M2 and M3 were later designed 
to deliver selective fire for greater combat ef- 
fectiveness, by the addition and modification of 
certain components. Thus the Ml and M1A1 
carbines are readily converted to give selective 
semi-automatic or full automatic fire by the 
substitution and addition of the necessary internal 

HOWEVER, the National Firearms Act 
ot 1968 levies a tax of $200 and demands reg- 
istration upon the making or transfer of any 

weapon capable of full automatic fire. Also, 
the possession of the parts necessary to convert 
a .30 carbine to selective fire — whether they are 
actually installed In the gun or not — is considered 
a violation of the law unless the special tax is paid 
In advance and the conversion is done with the 
knowledge and approval of the Alcohol, Tobacco 
and Firearms Bureau, U.S. Treasury Department 
(the agency which enthusiastically enforces the 
U.S. federal gun laws). Police and certain other 
authorized agencies can claim exemption from 
tha special $200 tax by applying to the above 
mentioned agency. 

plunger, recessed in the top of the dis- 
connector and bearing on the receiver, 
return the disconnector to the in- 
operative position, when the camming 
action of the lever is discontinued. 
(7) Disconnector lever assembly — added 

parts (Fig. 56). The disconnector lever 
assembly is not to be disassembled. 
Replace the lever assembly if any part 

A 'fin 

■ ■ ■- 

is found to be defective. The discon- 
nector lever assembly is composed of 
a disconnector lever pin* disconnector 
lever rivet, and disconnector lever. 
The pin retains the trigger housing 
when assembled to the receiver. The 
disconnector lever, riveted to a pivot 
on the pin, is shifted in a vertical plane, 
by the turning of the pin. The pin is 

■ ■ 

. J ,.— „.~~— - mmm f f -.^vrSS ^ir ■ ■ 




■ __ _ ' 

Figure 3a. Cal. ,30 carbine M3. 

Vv ■*,;*! 




^K SW« HlCClC* MftUW 

v ' r 

turned by the selector. A rounded 
projection on the rear end of the dis- 
connector lever operates the discon- 
nector. A projecting toe on the front 
end of the disconnector lever contacts 
the camming surface on the operating 
slide. An offset in the rear section 
provides for alignment with the dis- 
(8) Selector group — added parts (Fig. 56). 
The selector is mounted to the left end 
of the crank pin by means of a slot in 
the lower forward face of the selector 
mating the straddle slots in the end of 
the pin. The selector holds the pin in 
position and acts as a lever for turning, 
throwing the disconnector lever into 

or out of engagement with the oper- 
ating slide. A curved wire spring holds 
the selector in position on the pin and 

in the full automatic or semi-automatic 
position when operated. The straight 
front end of the spring seats into a 
recess in the lower rear end of the 
selector, and the circular rear end of 
the spring seats in a vertical slot in the 
front face of the magazine post on the 
left side of trigger housing. When 
assembled, the circular end of the 
spring is downward (spring is concave 

v- N 

Figure 3b. Operating parts for carbines M2 and M3. 


III. Mechanical Training 



The officers and noncommissioned officers 
of your unit will teach you how to take the carbine 
apart and how to put it together- This is commonly 
called field stripping. 


You will learn the names of the parts of your 
carbine during instruction in field stripping. As 
your instructor names the parts, repeat them to 
yourself and name each part as you remove it and 
as you replace it. You will find that the parts are 
generally names for the job they do. For example, 
the trigger guard actually guards the trigger so that 
your hands or some other object will not acci- 
dentally brush against the trigger and trip it. 


a. You will be permitted to disassemble only 
certain parts of your carbine, not because you can- 
not learn to disassemble all of them, but because 
constant disassembly causes extra wear. Also, 
some parts of your carbine require special tools 

for disassem bly . 

b. Study the following chart. The left-hand 

column shows those parts that you may disas- 
semble alone. The right-hand column shows those 
parts that only ordnance personnel may disas- 
semble. The center column indicates those parts 
that you may remove when supervised. 

1 " ~T 



BY — 

|MD|. fl 



1 1*1-* 1 11 












Gas cylinder piston 

* -r 

and piston nut 




Disconnector lever 



■ J 

Rear sight 


Front sight 


1 Magazine 


Operating slide group 





fc J 






These guides should be followed when disas- 
sembling and assembling the carbine. 

a. As the carbine is disassembled, lay out 
the parts from left to right on a clean flat surface 
in the order of disassembly. This procedure will 
help you as you assemble the carbine. 

b. Do not attempt to disassemble the carbine 

against time. 

c. If it is necessary to apply force, do it care- 
fully so you won't damage any of the parts, 


You must learn field stripping so well that 
you can do it in the dark. You can field strip your 



carbine by using only a screwdriver, or a dummy 
cartridge, and the operating slide spring guide. In 
combat, you may use a live cartridge. 


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Figure 4. Sliding the front band forward. 

. ■-*. ** 

Figure 5* Removing the hand guard. 


To field strip the carbine — 

a. Grasp the carbine with the left hand near 
the upper sling swivel. Grasp the magazine with the 
right hand, depress the magazine catch with the 
right thumb and remove the magazine. Do not 
drop the magazine. 

b. Unsnap and remove the sling from the 
upper sling swivel. Allow the sling to hang from the 
lower sling swivel (the oiler). During field strip- 



. . ":■. ' :'■ ■ .. 

Figure 6. Separating the stock group and the barrel 
and receiver group. 

ping, it is not necessary to remove the sling from 
the oiler, which serves as the lower sling swivel. 
However, should this step be required, remove the 
lower loop from the adjusting buckle and then 
withdraw the free end of the sling from around 
the oiler. Remove the oiler from its recess in the 

c- To remove the wooden hand guard, you 
must slide the front band forward toward the 
muzzle end of the weapon. To do this, grasp the 
carbine on your left hand with the front band 
screw head pointing to your right. Using a screw- 
driver or the rim of a dummy cartridge, loosen the 
front band screw about one-eighth of an inch. 
Depress the front band locking spring and slide 
the front band forward, disengaging it from the 
stock group and the hand guard (Fig. 4). If the 




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Figure 7. Removing the operating slide spring and 



front band sticks, place the bayonet lug over the 
edge of a table, depress the front band locking 
spring, pull downward on the carbine, and slide 
the front band forward. 

d. Move the hand guard forward until its rear 
end is disengaged from the groove in the front 
end of the receiver. Remove the hand guard 
(Fig. 5). 

e. Place the carbine on a level surface, muzzle 
left and sight up. Grasp the small of the stock with 
the right hand and the barrel with the left hand. 
Raise the muzzle end of the barrel about 15 
degrees until the recoil plate is released from the 
receiver (Fig. 6). Then separate the barrel and 
receiver group from the stock group. Place the 
stock group next to the hand guard. 

( t Place the barrel and receiver group on a 
level surface with the muzzle pointing to the left, 
sights down. With the right thumb and forefinger, 
pull the operating slide spring and guide to the 
rear, unseating the operating slide spring guide 
from its well in the receiver (Fig. 7). Remove the 
operating slide spring and guide and separate the 
two parts. The operating slide spring guide will 
be used as a tool in further disassembly, 

g. Now rotate the selector to the rear (semi- 
automatic setting). Insert the point of the oper- 
ating slide spring guide into the loop of the selector 
spring (Fig. 8). Push the loop end downward 
opposite its dismount notch and remove the 
selector spring. Move the selector forward to the 
automatic setting. Slide the selector to the rear, 
disengaging the slot of the selector from the 
straddle slots on the trigger housing and selector 




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Figure 9. 

Removing the disconnector lever as- 

Figure 8. Removing the selector spring. 

/?. To remove the disconnector lever assembly, 
push on the trigger housing and selector pin, 
unseating the disconnector lever (Fig, 9). Remove 
the disconnector lever assembly. If the discon- 
nector on your weapon has a slotted groove instead 
of a shoulder, disengage the rear end of the dis- 
connector lever before attempting to remove the 
disconnector lever assembly. To do this, unseat 
the disconnector lever assembly and then rotate 
the crank forward, disengaging the rear end of the 
disconnector lever from the slotted groove of the 
disconnector ( Fig. 1 0). Now, remove the dis- 
connector lever assembly. 

i\ Hold the barrel and receiver in the left 
hand with the muzzle to the left, sights up. 
Remove the trigger housing group to the rear 
(Fig. 11). Be careful not to lose the disconnector 
spring and plunger assembly. 

j. Place the barrel and receiver on a level 
surface with the muzzle to the front, sights up. 
Lift the rear of the barrel and receiver with the 
left hand. Grasp the operating slide handle with the 
right thumb and forefinger and draw the operating 
slide all the way to the rear. With an upward and 
outward pressure (Fig. 12-A), move the operating 
slide forward until the guide lug on the operating 
slide handle engages in its dismount notch. Pull 
to the right and up on the operating slide handle, 
partially disengaging the operating slide from the 
operating lug on the bolt. Grasp the heavy portion 
of the operating slide in the palm of the right hand. 
Move the operating slide forward about one-fourth 
inch, so that the left guide lug in the heavy portion 
of the operating slide is opposite its relief cut in 
the groove on the left under side of the barrel. 
Remove the operating slide by rotating it counter- 
clockwise (Fig. 12-B). 



Figure 10. Removing the disconnector lever as- 

ft. Hold the carbine as in j above. Grasp the 
operating lug of the bolt with the right thumb and 
forefinger and draw the bolt to the rear until its 
face is just back of the locking recesses. Rotate 
the bolt to the left until the operating lug is 
straight up, disengaging the left locking lug on the 
bolt. Then rotate the bolt to the right until it is 
level. Raise the bolt to an angle of about 45 
degrees and remove it from the receiver (Fig. 13). 

/. In Figure 14, you see the disassembled parts 
of the carbine laid out in the correct order. 


To assemble the carbine — 

a. Place the barrel and receiver on a level 
surface with the muzzle pointing to the front, 
sights up. Lift the rear of the barrel and receiver 
with the left hand. Grasp the operating lug of the 
bolt with the right thumb and forefinger. Place 
the base of the bolt over the bridge of the re- 
ceiver. Hold the bolt at an angle of 45 degrees with 

CnKO******* «■""»> "*D 't-l-»U" -W""*' 

the operating lug pointing to the right. Lower the 
bolt and engage its left locking lug in the groove 
in the receiver. Slide the bolt to the rear. 

b. With the barrel and receiver in the same 
position as in a above, move the bolt forward 
until its forward end is approximately 114 inches 
from the chamber. Hold the bolt in place with the 
left thumb as shown in Figure 15-A. Holding the 
heavy portion of the operating slide in the palm 

Figure 11. Removing the trigger housing group. 

Figure 12-A. Removing the operating slide. 

of the right hand, engage the operating lug of the 
bolt in the camming recess in the hump of the 
operating slide. Place the heavy portion of the slide 
so that the left guide lug is opposite its relief cut 
in the groove on the left under side of the barrel. 
Then, by rotating the operating slide to the right 
(clockwise), engage the two guide lugs in their 
grooves on the barrel (Fig. 15-B). Move the oper- 
ating slide and bolt to the rear until the operating 
slide handle guide lug engages in the dismount 





Figure 12-B. Continued. 

notch and is seated in its guide groove in the re- 
ceiver. Move the operating slide forward, closing 

the bolt. 

o. To replace the trigger housing group, first 

cock the hammer and replace the disconnector 

spring and plunger assembly if it was removed. 

Place the barrel and receiver on the palm of the left 

hand as shown in Figure 16. The operating slide 

handle is centered on and vertical to the palm of 

the left hand with the barrel and receiver canted 

slightly to the left. The fingers of the left hand are 

extended and joined. Pick up the trigger housing 

group in the right hand and engage its T lug with 

the corresponding slot on the receiver, from front 

to rear. As soon as the T lug is engaged, close the 

fingers of the left hand about the trigger housing 

group. You will hear a click. Align the trigger 

housing and selector pin holes, then pick up the 

disconnector lever assembly and lock the trigger 

housing group to the barrel and receiver group 

by inserting the trigger housing and selector pin 

through its holes from right to left. The toe of the 

disconnector lever should be pointing toward the 

muzzle of the carbine. You will have no trouble 
seating the disconnector lever assembly if the 
disconnector has a plain shoulder. If the discon- 
nector has a slotted groove, press inward on the 
rear of the disconnector lever and align the rear 
end of the lever with the slot of the disconnector. 
Pull the front end of the disconnector lever away 
from the operating slide. Now rotate the discon- 
nector lever to the rear, engaging its rear end in 
the disconnector groove. 

d. Place the barrel and receiver on a level 
surface with the muzzle pointing left, sights down. 
Engage the slotted portion of the selector with 
the straddle slot on the end of the trigger housing 
and selector pin. Rotate the selector to the rear. 

e. With the barrel and receiver in the same 
position as in d above, replace the selector spring 
by inserting its straight end into the recess in the 
rear of the selector (be sure the loop of the selector 

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Figure 13. Removing the bolt. 




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Figure 14. Lay out of parts disassembled during 
field stripping. 

spring points toward the trigger guard). Place the 
loop end of the spring in its dismount notch at the 
top of the groove on the trigger housing post. 
Using the operating slide spring guide, pull the loop 
end up, seating the selector spring. Notice in 
Figure 17 that the left thumb and forefinger are 
used to assist in replacing the selector spring. 
Move the selector back and forth several times to 
check the assembly. With the barrel and receiver in 
the same position as in d above, assemble the 
operating slide spring and guide. To replace these 
parts, insert the loose end of the operating slide 
spring into its well in the receiver. With the oper- 
ating slide forward, grasp the barrel and the heavy 
portion of the operating slide with the left hand. 
With the thumb and forefinger of the right hand 
on the shoulder of the operating slide spring guide, 
compress the operating slide spring and seat the 
operating slide spring guide in its recess. 

tm ■ 

f. Lower the rear end of the barrel and re- 
ceiver group into the stock group with the barrel 
at an angle of 15 degrees to the stock group. The 
retaining lug on the rear of the receiver must be 
inserted into the forward face of the recoil plate. 
The barrel will normally fail to seat completely 
in the stock. Do not attempt to force the barrel 
into place. To seat these parts, grasp the barrel 
and stock loosely, holding them at an angle of 
approximately 60 degrees to the horizontal and 
strike the toe of the butt against the ground 
(Fig. 18). This permits the recoil plate to spring 
over the retaining lug and prevents damage to 
these parts. The barrel will now fit into the groove 
in the stock without undue pressure being applied. 
g. With the carbine on a level surface, muzzle 
left, and sights up, replace the hand guard, en- 
gaging its liner in the groove in the receiver. Lock 


M I ^fr^ £» I*"*' ' 

Figure 15- A. Replacing the operating slide. 

Figure 15 B. Continued. 

the stock group, barrel and receiver group, and the 
hand guard together by sliding the front band 
down and over the forward ends of the hand guard 
and stock. Make sure that the front band passes 
over the front band locking spring. Tighten the 
front band screw, locking the front band in po- 

ft. Attach the forward end of the sling to the 
upper sling swivel. If the sling was completely 
removed, replace the oiler in its recess in the 
stock. Thread the rear end of the sling through its 
aperture in the stock, around the oiler, back 
through the aperture and through the adjusting 


To disassemble the trigger housing group - 

a. Squeeze the trigger and ease the hammer 

forward slowly to the fired position. Grasp the 



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Figure 16. Replacing the trigger housing group, 

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Figure 18. Assembling the stock group and the 
barrel and receiver group. 

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Figure 17. Replacing the selector spring. 

Figure 19. Removing the hammer spring and 
hammer spring plunger. 



. . . ■ 

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Figure 20- Removing the hammer pin, 

trigger housing group in the left hand as shown in 
Figure 19, With the right hand, insert the operating 
slide spring guide, or a similiar tool, into the hole 
in the hammer spring plunger from right to left 
and pull back until the hammer spring plunger is 
clear of the notch in the hammer (Fig, 19). Swing 
the hammer spring and plunger to the right to clear 
the hammer Ease forward against the force of the 
spring until the hammer spring plunger clears the 
trigger housing group* Remove and separate the 
hammer spring and the hammer spring plunger. 
If the operating slide spring guide is used, be care- 
ful not to bend it. 



b. With the operating slide spring guide, drift 
out the hammer pin (Fig, 20). Remove the hammer 
and disconnector. 

C. Hold the trigger housing group in the left 
hand as shown in Figure 21, with the thumb 
pressing down on the sear. Using the small end of 
the operating slide spring guide, drift out the 
trigger pin from right to left. Turn the trigger 
housing group upside down and allow the sear and 
sear spring to fall out. 

d. Hold the trigger housing group as shown 
in Figure 22. Move the trigger forward and then 
rotate the rear of the trigger upward and forward 
out of the top of the trigger housing group. Re- 
move the trigger spring from the trigger housing 
group during this step. 

Figure 21. Removing the trigger pin. 

Figure 22. Removing the trigger. 

e. Hold the trigger housing group in the left- 
hand as shown in Figure 23-A. With the right 
hand, insert the operating slide spring guide, or a 
similar tool into the hole in the lower face of the 
trigger housing — just forward of the bow. Engage 
the operating slide spring guide forward of the 
shoulder of the magazine catch retainer plunger 
and pull the plunger backwards. Place the left 
thumb against the magazine catch to prevent the 
magazine catch and the magazine catch plunger 
assembly (Fig, 23-A), from flying out. Remove 
the magazine catch and then the magazine catch 
plunger assembly from the trigger housing (Fig. 

f. Remove the magazine catch retainer plung- 
er assembly with the safety plunger attached 
(Fig. 24- A). Remove the safety from its aperture 
(Fig. 24-B). The magazine catch retainer plunger 
and safety plunger are identical and are positioned 
on opposite ends of the magazine catch retainer 
plunger spring. The spring actuates both plungers. 



g. In Figure 25, you see the parts of the 
trigger housing group laid out correctly in the 
order of disassembly. 

Figure 23-A. Removing the magazine catch. 

Figure 23-B. Removing the magazine catch plunger 


To assemble the trigger housing group — 

a. Hold the trigger housing as shown in 
Figure 19. Insert the safety into its aperture in the 
trigger housing with the trigger notch pointing 

to the rear. 

b. If you separated the magazine catch 
retainer plunger, safety plunger, and magazine 
catch retainer plunger spring, assemble these 
parts now. Remember, the two plungers are 
identical. Insert this assembly into its aperture in 
the magazine catch guide groove. 

c. If you separated the magazine catch spring 
and plunger, assemble these parts now, and then 
place the assembly in its well in the trigger guard 
housing. The loose end of the magazine catch 
spring is inserted first, with the plunger facing 
outward. Replace the magazine catch into its guide 
groove in the forward face of the trigger housing 
with the fingerpiece facing to the rear. Move the 
magazine catch to the left against its plunger. 
Grasp the trigger housing as shown in Figure 26. 
Pull the magazine catch retainer plunger back into 
the aperture in the trigger housing and at the same 
time, push the magazine catch completely to the 
left. The magazine catch retainer plunger will 
click into position in its recess in the magazine 
catch, holding the magazine catch in its guide 
groove. Operate the safety and magazine catch a 
few times to test the assembly. 

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Figure 24-A. Removing the magazine catch re- 
tainer plunger assembly. 

d. Hold the rear of the trigger housing group 
in your left hand. Grasp the long forward end of 
the trigger with the right thumb and forefinger. 
Hold the trigger level and place it down into the 
trigger housing group with the fingerpiece pro- 
jecting part way through the floor of the trigger 
housing. Grasp the fingerpiece with the thumb and 
forefinger of the left hand which is holding the 
trigger housing group (Fig. 27). Position the 
trigger spring to the rear of the trigger so that the 
loop end rests in the slot in the rear top face of the 



Figure 24-B. Removing the safety. 

trigger. The prongs of the spring point upward 
and bear upon the upper edge of the trigger spring 
aperture (Fig. 28). This aperture is the lower of 
the two apertures in the rear of the trigger housing. 
With the right forefinger over the trigger and 
trigger spring to hold them in position, press down 
and to the rear, allowing the fingerpiece of the 
trigger to rotate forward and upward. When the 
coils of the trigger spring are seated in the aperture, 
pull back on the fingerpiece of the trigger to seat 
it in the trigger housing group. Do not pull back 
on the trigger until the coils of the trigger spring 
are seated, or the trigger spring will fly out. Align 
the trigger pin holes in the trigger and trigger 
housing, then insert the trigger pin from the left 
side just far enough to hold the trigger in position. 

e. Insert the sear spring in the forward face 
of the trigger. Place the sear in position on top of 
the trigger, with the raised shoulder up and point- 
ing toward the front of the trigger housing. The 
free end of the sear spring must be seated in the 
rear face of the sear. Hold the trigger housing 

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group in the left hand as shown in Figure 29, 
with the forefinger pressing against the trigger pin. 
Force the sear to the rear by applying pressure 
against its raised shoulder with the operating 
slide spring guide. At the same time, maintain 
pressure against the rear of the sear with a finger 
of the right hand and align the trigger pin holes. 
Seat the trigger pin. 

f. Replace the disconnector, making sure that 
its rear end is on top of the sear (Fig. 30). Re- 
place the hammer with its long end up and curving 
to the rear (Fig. 31). Engage the sear notch of the 
hammer with the sear nose and rotate the hammer 

Figure 25. Layout of the parts of the trigger 

housing group. 

Figure 26. Replacing the magazine catch. 

to its rearward (cocked) position. Align the ham- 
mer pin holes and replace the hammer pin. The 
operating slide spring guide may be used to align 
the hammer pin holes. 

g. Squeeze the trigger and move the hammer 
forward to its fired position. Assemble the hammer 
spring and hammer spring plunger. Seat the free 
end of the hammer spring in its well in the trigger 
housing group with the head of the hammer spring 
plunger on the right side of the hammer. Insert 



<■■'.: <i *«* : 


Figure 27. Replacing the trigger. 


UOOP > - 

the operating slide spring guide into the hole 
in the hammer spring plunger. Pull the hammer 
spring plunger back against the force of the ham- 
mer spring and seat it into the well in the hammer. 


The operating slide stop is the only removable 
part of the operating slide group. To disassemble 
the operating slide group — 

a. Grasp the operating slide as shown in 
Figure 32. Using the operating slide spring guide, 
push out the operating slide stop, small end first. 

b. Remove the operating slide stop spring 
from the well in the operating slide. 

Figure 28. Trigger spring in proper position. 

Figure 29. Replacing the trigger pin. 


To assemble the operating slide group — 

a. Replace the operating slide stop spring 
into its well in the rear of the slide. 

b. Replace the operating slide stop, large end 
first, into the bottom of its well. Using the oper- 
ating slide spring guide, depress the operating 
slide stop spring and seat at the operating slide 


To disassemble the magazine — 
a. Grasp the magazine in the left hand with 
the base up and with the rounded end of the base 







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Figure 30. Replacing the disconnector. 

toward your body (Fig. 33). With the left thumb, 
press up on the rounded end of the magazine 
base until you can move it from the retaining 
grooves in the base of the magazine tube by 
pushing to the left with the operating slide spring 

b. Turn the magazine on end and drop out 
the magazine spring. 

c. Allow the follower to slide to the bottom 
of the magazine tube. Grasp the flange on the 
follower and rotate the follower out of the maga- 
zine tube. 


To assemble the magazine, proceed in the 
reverse order of disassembly. 


a. By taking your carbine apart and putting 
it together you become familiar with its parts. 
Next, you learn how these parts function. If you 
understand how your carbine works, you will be 
able to keep it in working order. This knowledge 
will give you confidence in your carbine. 

6. Each time a cartridge is fired, many parts 
inside the carbine work in a given order. This is 
known as the cycle of functioning. This cycle 
is almost the same in all semi-automatic weapons. 

c. To help you understand the cycle of 
functioning, it is broken down into eight basic 
steps. Keep in mind that more than one step may 
be occurring at the same time. The steps are listed 
below in the order that they begin. 


Figure 31. Replacing the hammer. 



(1) Feeding — moving the cartridge into 
the path of the bolt. 

(2) Chambering — moving the cartridge 
into the chamber. 

(3) Locking — locking the bolt in the 

(4) Firing — driving the firing pin forward 
to strike the primer, which sets off the 

(5) Unlocking — unlocking the bolt from 
the receiver. 

(6) Extraction — removing the empty 
cartridge case from the chamber. 

(7) Ejection — throwing the empty car- 
tridge case from the carbine. 

(8) Cocking — pushing the hammer into 
the cocked position. 

d. During the discussion of functioning of 
the trigger housing group you will find the names 
of many new surfaces and parts. To help you 
locate these parts and surfaces, Figures 34 through 
37 have been included. 



Figure 32. Removing the operating slide stop. 


a. Since the carbine begins to function when 
you squeeze the trigger, you first learn how the 
trigger housing group works (Fig. 38). 

(1) Remove the trigger housing group and 
cock the hammer. The hammer is held 
in the cocked position by the sear nose 
engaging the sear notch on the hammer. 
Hold your left thumb over the hammer 
and slowly squeeze the trigger. Notice 
how the trigger lip moves upward and 
contacts the rear of the sear. This 
action forces the sear to pivot about 

Figure 33. Removing the magazine base. 

the trigger pin. As the sear pivots, 
its forward end moves downward and is 
disengaged from the hammer. The 
hammer is forced forward by the 
expanding hammer spring. This hap- 
pens each time the trigger is squeezed 
if you release your finger from the 
trigger after each shot is fired. 
(2) There must also be a way of stopping 
the hammer from going forward, even 
if you keep your finger pressed on the 
trigger after each shot. This is ac- 
complished by the sear nose engaging 
in the sear notch as the hammer starts 
forward. The action causes the sear to 
move to the rear a short distance 
against the action of the sear spring. 
The sear cannot move completely to 
the rear because it is blocked by the 
trigger lip. Now release the trigger and 
squeeze it again, holding it to the 
rear. Cock the hammer slowly and see 
how the sear moves to the rear a short 
distance and the sear nose engages the 



:■■■■ trigger housing . .. '. 
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Figure 34. Trigger housing group parts. 




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Figure 35. Trigger housing group parts. 

sear notch, holding the hammer back. 
Release the trigger slowly. As you do 
this, the sear moves farther to the rear 
and the hammer moves forward a short 
distance and then stops. The hammer is 
still held in the cocked position hy the 
sear nose engaging the sear notch. 
This combination holds the hammer to 
the rear each time a round is fired. 
b. As you apply pressure on the trigger it 
pivots about the trigger pin. This movement is 
divided into a slack portion and a squeeze portion. 
Cock the hammer and squeeze the trigger lightly. 
Notice that it moves easily until the trigger lip 
touches the rear end of the sear. This movement, 
until the trigger lip contacts the sear, is called 
the slack. Increased pressure is required to move 
the trigger from the time the trigger lip contacts 
the rear of the sear until the sear nose releases the 
sear notch on the hammer. This second movement 
of the trigger which requires heavier pressure is 
called the squeeze. 


When the carbine is fired automatically, 
the trigger housing group functions almost the 
same as on the semi-automatic setting. On the 
automatic setting, however, each time the oper- 
ating slide moves forward the rear end of the 

disconnector lever is rotated upward causing 
the disconnector to pivot about the hammer pin. 
When the trigger is held to the rear, the rear of 
the disconnector contacts the raised shoulder of 
the sear and forces the forward end of the sear 
down, disengaging the sear nose from the hammer. 
The hammer moves forward actuated by the ham- 
mer spring, and the carbine fires. If the trigger is 
released, the sear moves to the rear under action 
of the hammer spring, and the rear of the dis- 
connector cannot contact the forward end of the 
sear. The sear nose remains engaged with the 
hammer, the hammer is held to the rear, and the 
carbine stops firing. 




!:.:,._ _ ' 

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. ■ !■■ 



Figure 36, Trigger housing group parts. 



Figure 37. Trigger housing group parts. 



..,:.. a 


Figure 38. Functioning of trigger housing group. 


The action of the working parts during the 
functioning cycle is divided into two phases with 
certain steps of each phase going on at the same 
time. They are listed below in the order in which 

they start. 

a. The firs* phase is the ACTION DURING 

(1) Chambering. 

(2) Locking. 

(3) Alignment of the firing pin. 

(4) End of the forward movement. 

ft. The second phase is the ACTION DURING 

( 1 ) Action of the gas. 

(2) Action of the operating slide and 

(3) Unlocking. 

(4) Withdrawl of the firing pin. 

(5) Extraction. 

(6) Ejection. 

(7) Cocking. 

(8) Feeding. 

(9) End of the rearward movement. 


a. Chambering. As the operating slide and bolt 
move forward, pushed by the compressed operat- 
ing slide spring, the bolt strips off the top round 
in the magazine and shoves it into the chamber. 
When the bolt reaches its forward position, the rim 
of the cartridge is gripped by the extractor. The 
base of the cartridge forces the ejector into the 
bolt, compressing the ejector spring. 

b. lacking. When the bolt is all the way 
forward, the rear camming surface in the hump of 
the operating slide forces the operating lug of the 

bolt downward, making the bolt rotate clockwise. 
The bolt is locked as the locking lugs on both 
sides of the bolt engage the locking recesses in the 

c. Alignment of the Firing Pin. Slightly 
before the bolt reaches its foremost position, the 
tang of the firing pin contacts the bridge of the 
receiver, stopping the forward movement of the 
firing pin. When the bolt is turned and fully 
locked, the tang of the firing pin is aligned with 
the slot in the bridge of the receiver and may be 
driven forward by the hammer. This is a safety 
feature to make sure that the bolt is fully locked 
before the live cartridge can be fired. Should the 
hammer fall before the bolt is fully locked, the 
bolt camming lug on the hammer will strike the 
cocking cam on the bolt causing the bolt to rotate 

to its locked position. 

d. End of the Forward Movement. After the 
bolt has been turned into the locked position, 
the operating slide continues forward a short 
distance. The forward movement of the operating 
parts ends when the inside of the heavy portion 
of the operating slide has driven the gas piston 
into the gas cylinder. 


a. Action of the Gas. When a cartridge is fired, 
the gas formed by the burning powder provides 


Figure 39. Functioning of operating parts (semi- 
automatic setting). 



Figure 40. Action of the gas. 

the force for the rearward movement of the 
operating parts. A chamber pressure of approx- 
imately 40,000 pounds per square inch is gener- 
ated and the bullet is forced through the barrel 
by the expanding powder gases. A small part of 
this gas, seeking the easiest means of escape, 
expands through the gas port into the gas cylinder 
and strikes the piston with a sudden force, driving 
the operating slide to the rear (Fig. 40). 

6. Action of the Operating Slide and Spring, 
As the operating slide starts to the rear, the oper- 
ating slide spring begins to be compressed. The 
operating slide moves to the rear approximately 
five-sixteenth of an inch before contacting the 
operating lug of the bolt. This allows it to build 
up enough speed to overcome the inertia of the 
locked bolt. This free play is also a safety feature. 
It allows the bullet to clear the muzzle, allowing 
the pressure inside the barrel to be reduced to 
outside pressure before the bolt begins to unlock. 
This prevents a blowback of gases into your face. 

c. Unlocking. As the operating slide continues 
to the rear, the front camming surface in the hump 
of the operating rod contacts the operating lug on 
the bolt, turning the bolt counterclockwise, un- 
locking it. 

± Withdrawal of the Firing Pin. This action 
occurs at the same time the bolt is being unlocked. 
As the bolt is turned counterclockwise, the tang 
of the firing pin contacts the bridge of the receiver. 
The firing pin is forced to the rear, withdrawing 
the striker of the firing pin into the face of the 

e. Extraction. Extraction occurs next (Fig. 
41). Remember that the extractor has been grip- 
ping the rim of the cartridge case all the time that 
the cartridge has been in the chamber. Initially 
the cartridge is loosened in the chamber as the 
bolt unlocks, due to a very slight rearward move- 
ment of the bolt. As the bolt continues to the rear 
it pulls the empty case from the chamber 

f Ejection. When the front of the empty 
cartridge case clears the rear of the chamber, 
the ejector (which has been continually pushing 
against the base of the case) ejects the empty case 
from the receiver by the action of the expanding 
ejector spring (Fig, 41). 

g. Cocking. As the bolt moves to the rear, 
it forces the hammer rearward and downward into 
the cocked position. 

h* Feeding. When the bolt in its rearward 
movement clears the top round in the magazine, 
the follower, through the action of the compressed 
magazine spring, moves the top cartridge up into 
the path of the bolt. 

t End of the Rearward Movement The 
rearward movement ends when the heavy portion 
of the operating slide contacts the front of the 


a t Semi-automatic Setting, When the selector 
is in the rear (semi-automatic) position, the dis- 
connector lever is disengaged and is not involved 
with the functioning of the carbine. Since the 
disconnector lever is lowered and its toe cannot 
contact the camming surface on the operating 
slide, the selector is held on either setting by the 
locking action of the selector spring- 

Figure 41. Extraction and election. 



b. Automatic Setting. When the selector 
is pushed forward, it rotates the trigger housing 
and selector pin. The crank on the trigger housing 
and selector pin rotates upward forcing the dis- 
connector lever upward. Assuming that the oper- 
ating slide is forward when the disconnector lever 
moves upward, the toe of the disconnector lever 
contacts the camming surface on the operating 
slide. The toe of the disconnector lever is forced 
down, making the disconnector lever pivot on the 
trigger housing and selector pin. The rear end of 
the disconnector lever is raised. This raises the 
front end of the disconnector, which compresses 
the disconnector spring and plunger assembly. 
The disconnector pivots about the hammer pin, 
rotating downward the projecting lug on the rear 
of the disconnector. If the hammer were cocked 
and the trigger squeezed, the disconnector would 
bear against the raised shoulder of the sear. The 
forward end of the sear would be depressed and 
the hammer would be released. However, with the 
trigger released, the sear has moved far enough to 
the rear so that the disconnector cannot contact 
the sear. Hence, the hammer is not released. The 
sear is forced to the rear by the hammer spring. 


a. The action as the operating slide moves 
forward is the same as on the semi-automatic 
setting (Page 28) and (Fig. 39), up to the time 
the camming surface on the operating slide 
contacts the toe of the disconnector lever. At this 
point, the operating slide cams down the toe of 
the disconnector lever. This raises the rear end of 
the disconnector lever, which is in contact with 
the disconnector. The forward end of the dis- 
connector is cammed upward. The disconnector 
rotates about the hammer pin, and the projecting 
leg on the rear of the disconnector moves down- 
ward. With the trigger still held back, the project- 
ing lug of the disconnector presses against the 
raised shoulder of the sear and the sear nose is 
disengaged from the hammer. The hammer spring 
then rotates the hammer forward, and the carbine 
fires. This happens every time the operating slide 
moves forward if pressure is maintained on the 
trigger (see next column). 

b. The operating slide cams the toe of the 
disconnector lever down during the last five- 
sixteenth inch for forward movement of the slide. 
Thus the bolt is fully rotated and locked before 
the carbine is fired. As in the Ml carbine, the 

bridge of the receiver keeps the firing pin from 
moving forward before it should. 

c. If the trigger is released, the sear will move 
back over the trigger lip far enough to move the 
sear out of possible engagement with the discon- 
nector. Therefore, the disconnector will not dis- 
engage the sear from the hammer. The sear in this 
case continues to hold the hammer in the cocked 


a. The action up to the time the operating 
slide starts to the rear is the same as on the semi- 
automatic setting (Page 28). In the first half inch 
of rearward movement of the operating slide, the 
toe of the disconnector lever slides off the cam- 
ming surface on the operating slide and rises. 
Since pressure is no longer held against the dis- 
connector, the disconnector spring and plunger 
assembly forces the front of the disconnector, 
as well as rear of the disconnector lever, down- 
ward. As the disconnector pivots about the ham- 
mer pin, the projecting lug on the rear of the dis- 
connector rises to clear the sear. 

b. The remainder of the rearward movement 
is the same as on the semi-automatic setting. 


■ ■ 


Figure 42. Functioning of operating parts (auto- 
matic setting). 





a. The Safety. To see how the safety works, 
cock the hammer and rotate the safety downward 
to the safe position. As you rotate the safety 
downward the trigger notch in the safety rotates 
to the rear and in its place the solid portion of the 
safety is exposed to the forward end of the trigger. 
Attempt to squeeze the trigger. The solid portion 
of the safety now blocks the forward end of the 
trigger, preventing the trigger from moving. Since 
the trigger cannot move, the hammer remains 
stationary and the weapon does not fire (Fig. 43). 

b. The Bolt and Firing Pin. A safety feature 
has been built into the carbine to prevent it from 
firing unless the bolt is in its locked position. 
This is done by the action of the bolt camming 
lug on the hammer against the cocking cam of the 
bolt. Note on your weapon that if the bolt is not 
completely rotated to the right into the locked 
position, the bolt camming lug will not fit in the 
cocking cam and the hammer cannot hit the tang 
of the firing pin. If the bolt is not fully locked as 
the hammer moves forward, the bolt camming lug 
will rotate the bolt to the right. This action locks 
the bolt before the hammer can hit the tang of 
the firing pin. During unlocking, the instant the 
bolt starts to rotate to the left, the hammer is 
pushed away from the tang of the firing pin by 
the action of the cocking cam against the bolt 
camming lug. 

Figure 43* How the safety works. 


To use your carbine, you must know how to 
load it with a magazine and with a single cartridge. 
You must know how to fire it, and, for the safety 
of yourself and others, how to unload and clear 
it. In this section, you will be shown how to do 
these things. 


Insert the desired number of cartridges (max- 
imum of thirty) in the magazine so that the base 
of each cartridge is close to the rear wall of the 


Holding the carbine with the left hand at the 
balance, rotate the safety downward. With the 
right hand, insert a fully loaded magazine into 
the magazine opening, making sure that it snaps 
into place. Tap up on the magazine* base to be sure 
it is seated. With the forefinger of the right hand, 
pull the operating slide quickly to the rear and 
release it, closing the bolt. Striking the operating 
slide handle sharply with the heel of the right hand 
helps to close and lock the bolt. 


a. To unload the carbine, move the safety to 
the safe setting, remove the magazine and lock the 
bolt in the open position. There are two methods 
for removing the magazine. 

6. To unload a single round from the cham- 
ber, hook the right forefinger over the operating 
slide handle and pull the operating slide to the 
rear. This extracts and ejects the round. 


With the receiver empty, pull the operating 
slide to the rear and lock it in this position by 
depressing the operating slide stop. With the right 
hand, place one round in the chamber, seating 
it with the thumb. With the right forefinger, pull 
the operating slide slightly to the rear and release 
it. The operating slide must be allowed to go for- 
ward by the force of its expanding spring. It must 
not be slowed in its forward movement by contact 
with the hand. If the operating slide is not com- 



pletely released, the bolt may not lock. When this 
occurs, the carbine may not fire when the trigger 
is squeezed. 


To fire the carbine semi-automatically, move 
the selector to the rear and squeeze the trigger 
for each shot. 

Figure 43a. The rear sight. 


a. When the carbine is firea automatically, 
accuracy is sacrificed for an increased volume of 
fire. Therefore, automatic fire should be used only 
when a large volume of fire is needed at very close 
ranges. You should be trained in the capabilities 
and limitations of this type of fire so that you can 
use it to the best advantage, keeping in mind such 
things as the availability of ammunition, the 
decrease in accuracy when firing automatically, 
and the demoralizing effect on the enemy. 

b. To fire the carbine automatically, push the 
selector forward. When pressure is applied to the 
trigger, the carbine will fire as long as the trigger is 
held back and there is ammunition in the maga- 
zine. To cease firing, release the trigger. 

Caution: Always release the trigger before 
shifting the selector to automatic. If the trigger 
is held back with the hammer cocked and the 
selector pushed forward to the automatic position, 
the carbine will fire. 


The loaded carbine must be kept locked until 
you are ready to shoot. To lock the carbine, 

rotate the safety downward to its "ON" position. 
In this position, the trigger cannot be moved 
because the forward end of the trigger is blocked 
by the safety. When locked, the carbine may be 
loaded or unloaded by hand but it cannot be 
fired. To unlock the carbine, rotate the safety 
rearward to its "OFF" position. 


To clear the carbine, unload it as explained 
in paragraph 30. Glance into the chamber and 
receiver to see that there are no cartridges in the 
weapon. Leave the bolt open. 


a. The rear sight of your carbine is adjustable 
(Fig. 43o), enabling you to engage targets ac- 
curately up to the maximum effective range. It 
has an elevation slide and a windage knob. The 
rear sight ramp has the numbers 1, 2, 2.5, and 3 
corresponding to 100, 200, 250, and 300 yards of 
range. There is a corresponding indentation on the 
ramp for each of these ranges. The sight setting 
for 100 yards is also used for firing at 150 yards. 
The base of the rear sight has graduations for 

b. To raise the strike of the bullet on the 
target, increase the sight setting by moving the 
elevation slide toward you. To lower the strike 
of the bullet on the target, lower the sight setting 
by moving the elevation slide away from you. 
To move the strike of the bullet to the right, turn 
the windage knob away from you. This moves 
the aperture to the right and is called right wind- 
age. To move the strike of the bullet to the left, 
turn the windage on the rear sight. An easier 
way of saying all this is to move the rear sight in 
the direction that you want to move the strike of 
the bullet. 

c. After setting the rear sight to any click of 
elevation or windage, move the adjustment knob 
or slide slightly in both directions to see that it is 
centered for that click. 


With the carbine fully assembled and un- 
loaded, and the safety rotated upward (firing 
position), the following operation checks may be 


a. Pull the selector to the rear (semi-auto- 
matic position). With the trigger released, pull the 



operating slide to the rear, cocking the hammer. 
Allow the operating slide to snap forward. The 
hammer should not fall, 

b. With the trigger held to the rear, pull the 
operating slide to the rear, cocking the hammer. 
Allow the operating slide to snap forward. The 
hammer should not fall until the trigger is released 

and then squeezed- 

c. With the trigger released, pull the oper- 
ating slide to the rear, cocking the hammer. Allow 
the operating slide to snap forward. Push the 
selector to the forward (automatic) position. 
The hammer should not fall until the trigger is 


d. With the selector in the forward (auto- 
matic) position, pull the operating slide to the rear, 
hold the trigger back, and allow the bolt to close 
slowly- The hammer should not fall until the bolt 
is fully locked. 

e. Test the safety with the selector in both 
positions. The hammer should not fall when the 
safety is moved to its "OFF" position. 


Safety cannot be overemphasized. Some of 
the precautions to observe in handling the carbine 
follow. These precautions are not intended to 
replace other existing safety regulations. 

a. A carbine with its bolt closed is never 
considered to be safe until it is properly inspected. 

b. Do not playfully or carelessly point the 
carbine at anyone. Always consider the carbine 


c. Do not leave any obstruction in the muzzle 

or bore. 

d. Never push the selector forward to the 

automatic position while maintaining pressure 
on the trigger. If the trigger is held back with the 
hammer cocked and the selector pushed forward 
to the automatic position, the carbine will fire. 



If your carbine stops firing through no fault 
or intention of your own, then you have a stop- 
page. You must be able to clear such stoppages 
and continue firing. In combat your lift may de- 
pend on your ability to reduce a stoppage quickly 
so you can continue to deliver accurate fire. 
Therefore, the first thing to do when you have a 
stoppage is to apply immediate action. This is the 

unhesitating application of a probable remedy 
to clear a stoppage without investigating the 


If your carbine fails to fire, pull the operating 
slide all the way to the rear with the right hand, 
palm up; release it, aim, and attempt to fire. 
This action will clear most stoppages. If this fails 
to correct the stoppage and your weapon will not 
fire semi-automatically, work the operating slide 
by hand until you have enough time to investigate 
the trouble. 


a. The stoppages that are not cleared by 
immediate action fall into three classes. 

(1) Failure to chamber is caused by some 
condition that prevents the bolt from 
chambering the cartridge completely, 

(2) Failure to fire is caused by the primer 
failing to fire when struck by the 
firing pin or a failure of the firing pin 
to strike the primer, 

(3) Failure to extract is caused by an 
extremely dirty chamber or ammu- 
nition, or by a broken extractor or 


b, Table I gives the causes for these and other 
stoppages and tells you what action to take to 
correct them- 



Your carbine will be only as good as the care 
that you give it. Rust and dirt cause more wear 
than firing, and more carbines become unservce- 
able through lack of care and cleaning than for any 
other reason. 


a. Cleaning Materials. 

(1) Rifle bore cleaner is provided for clean- 
ing the bore of your carbine after 
firing- It may be placed in the bore of 
your weapon after firing and left there 
for several hours until you can clean 
the weapon and apply a preservative 
oil. This material has rust-preventive 



properties. After using rifle bore 
cleaner, dry the fore and apply a thin 
coat of preservative lubricating oil- 
Rifle bore cleaner freezes at temper- 
atures below minus 20 degrees F. 
If thawed rifle bore cleaner is used, 
shake it well before using. 
(2) Soap and water (warm or cold) is used 
for cleaning the bore when the rifle 
bore cleaner is not available. Warm 
water alone is good, but warm soapy 
water is better. After using soap and 
water, dry the bore thoroughly and 

apply a thin coat of light preservative 
lubricating oil. 

( 3 ) Vo la t ile-m in e ra l-sp iri t$-p ain t thin ne r 
and dry 'Cleaning solvent are non- 
corrosive solvents used for removing 
grease, oil, or light rust-preventive 
compounds from weapons. Do not use 
these solvents near an open flame, 
because they are highly inflammable. 
Smoking is prohibited where these 
solvents are being used. They will 
attack and discolor rubber. Apply 
with rag swabs to large parts and use 

Table 1. Stoppages and Malfunctions 




Failure to chamber. 

(1) Dirty or rough chamber. 

{1} Clean chamber. 

(2) Restricted gas port. 

(2) Clean gas port. 

(3) Dirty or improperly lubri- 

(3) Clean and lubricate carbine. 

cated carbine. 

{4} Damaged magazine. 

(4) Replace magazine. 

(5) Ruptured cartridge case 

(5) Remove ruptured cartridge 

in chamber. 


Failure to fire {hammer 

(1) Bolt not seated and locked. 

(1) Pull operating slide halfway 

releases but carbine does 

to the rear and release it. 

not fire). 

Insure complete locking. 

(2) Defective or broken 

(2) Replace bolt. 

firing pin. 

{3) Defective ammunition. 

(3) If practicable, secure new 


Failure to extract. 

(1) Dirty or rough chamber. 

{1) Clean chamber. 

(2) Restricted gas port. 

(2) Clean gas port. 

(3) Dirty ammunition. 

(3) Clean cartridge or, if 
practicable, secure new 

{4) Broken extractor. 

(4) Replace bolt. 

Fires in bursts of two or 

(1 ) Sear broken or worn, or re- 

0) Replace sear. 

three rounds (rare). 

mains in open position. 

Pressure on trigger does 

(1) Deformed hammer or trigger. 

{1) Replace defective part. 

not release hammer. 

(2) Broken trigger spring. 

(2) Replace trigger spring. 

Selector cannot be moved 

0) Selector spring incorrectly 

(1) Place selector spring in proper 

from automatic to semi- 

assembled in trigger housing 

position, loop toward trigger 

automatic setting. 



Disconnector fails to 

{ 1 ) Projecting lug on rear of 

(1) Replace disconnector. 


disconnector is broken. 

Selector shifts to semi- 

(1) Broken or weak selector 

{1} Replace selector spring. 

automatic when firing 


automatic fire. 



as a bath for small parts. Clean all 
surfaces immediately and dry them 
thoroughly with clean rags. Then oil 
the parts. Since perspiration contains 
corrosive acids, avoid leaving finger 
(4) Decontaminating agents are used under 
special conditions to remove chemical 
agents (Page 38). 

b. Lubricants. 

(1) Medium preservative lubricating oil 
is superior to special preservative 
lubricating oil for small arms exposed 
to salt-water atmosphere. It is heavier 
and possesses better preservative char- 
acteristics which make it useful for 
coating all parts of the weapon before 
landing operations. Use it in prefer- 
ence to special preservative lubricating 
oil when the carbine is to be exposed 
to salt water and at temperatures 
above +32 degrees F. 

(2) Special preservative lubricating oil 
is a thin oil used for lubricating at 
temperatures below +32 degrees F. 
and for providing temporary protection 
against corrosion. Use this oil for 
preserving the bore after the carbine 
has been fired and cleaned, as well as 
for lubricating all moving parts. When 
used on moving parts, it is necessary 
to maintain a thin film of oil to provide 
proper lubrication. Make frequent 
inspections to to see that you have an 
adequate protective film of oil. 

(3) Rifle grease possesses good resistance 
to the action of water. Use it sparingly 
on those parts subject to heavy wear in 
wet climates or during amphibious 
operations. Figure 45 shows the parts 
where this grease should be applied. 
It is issued in a small plastic container. 

(4) Engine oil, SAE 10 may be used when 
the oils mentioned above cannot be 
obtained. In cold weather, any oil as 
heavy as this causes sluggish operation 
and may prevent the carbine from 
working. This oil does not possess the 
rust-preventive properties of preser- 
vative lubricating oils. When engine oil 
is used, the weapons must be examined, 
cleaned, and reoiled frequently. 

c. Preservatives. 

(1) Medium rust-preventive compound 

is issued for protecting the metal 
parts for long periods while the car- 
bines are boxed and in storage. Warm 
it before application. 
(2) Raw linseed oil is a vegetable oil used 
to prevent the drying of the wooden 
parts and to preserve them; and it 
improves the appearance of the wood. 
Apply it with long strokes of the 


a, General. This includes the care of the 
carbine to preserve its condition and appearance 
during the periods when no firing is done. Car- 
bines in the hands of troops should be inspected 
daily to insure proper condition and cleanliness. 

b. Bore. 

(1) When you clean the bore, the magazine 

should be out and the bolt should be in 
the open position. The bolt normally 
can be held in the open position by 
the operating slide stop. Since the bolt 
can be released easily, you may place 
a piece of wood, or some similar object, 
between the hump of the operating 
slide and the rear of the hand guard to 
hold the bolt to the rear. 

(2) To clean the bore, use the M8 cleaning 
rod and several patches. If you use a 
rod longer than the M8, protect the 
face of the bolt against damage from 
the rod. Run a clean, dry patch forward 
and backward through the bore several 
times, making sure that the patch 
goes all the way through before re- 
versing the direction. Repeat this 
several times, using a clean patch each 
time, until a patch comes out clean. 
Then, dip a patch in preservative 
lubricating oil, squeeze out the excess 
oil and run the patch through the 

bore several times. 

Caution: Avoid careless use of the 
cleaning rod to prevent unnecessary 
wear at the muzzle; do not allow the 
cleaning rod to bear against the bore 

at the muzzle. 
c. Disconnector Group. See that the camming 
slot in the front end of the disconnector is free 
from foreign matter and is not burred; the dis- 
connector plunger spring is not weak, rusted, or 
broken; the well for the disconnector spring and 



plunger assembly is clean; and the disconnector 
plunger is not burred. Oil these parts lightly. 
The expanded end of the disconnector spring 
should be seated in the disconnector plunger. 
Check the rear of the disconnector for burrs and 

d. Disconnector Lever Assembly, See that 
the pivot on the crank end is not worn and is free 
from burrs, and that the straddle cuts on the 
trigger housing and selector pin are not worn. 
Such wear causes lost motion. Also check the 
disconnector lever to make sure it is straight and 
free from burrs. The rear of the disconnector 
lever assembly should not bind in the slotted 
groove or shoulder of the disconnector. Oil the 
assembly lightly. 

e. Selector Group. Clean the selector spring 
recess. Check the selector spring to see that it is 
not twisted and does not fit too loosely. If the 
selector spring is too loose, straighten it slightly- 

t Trigger Housing. See that the selector 
spring retention slot in the trigger housing group is 
free from dirt and seats the selector spring securely 
so that it will not turn. 

g Operating Slide. Oil the disconnector lever 
cam on the operating slide. See that this surface is 
free from burrs. 

/*, Magazine Catch. See that the projection 
on the left side of the magazine catch is not 


L Stock, See that the stock is neither so 
swollen nor warped that it will interfere with the 
action of the disconnector, disconnector lever, 
or selector. 

j. Screw Heads and Recesses. Clean the small 
screw heads and all recesses with a small brush 
or stick. An old tooth brush or shaving brush is 
excellent for this purpose. Clean the metal parts 
with a dry cloth and wipe with an oil-dampened 
cloth to provide a protective finish. Wipe the stock 
and hand guards with a clean cloth, then rub in 
linseed oil. 

Caution: After cleaning your carbine, do not 
use a muzzle plug or cover. They cause moisture 
to collect, and result in rust; and there is always 
the danger of forgetting to remove the plug before 

6, Clean the bore and chamber. Do not oil 

c. Remove any carbon from the head of the 
piston nut 

& Clean thoroughly all metal parts which do 
not come in contact with the ammunition and put 
a light coat of oil on them. Use special or medium 
preservative lubricating oil. Be sure that the fol- 
lowing parts have a light coat of oil: 

(1) Locking lugs and the operating lug of 

the bolt and their recesses. 

(2) Bolt guide grooves in receiver, 

(3) Cocking cam on rear of bolt and firing 
pin tang recess. 

(4) Contact surface of barrel and operating 

{5) Operating slide spring guide. 

(6) Operating slide handle grooves on side 
of the receiver. 

(7) Operating slide grooves in barrel. 

(8) Contacting surface of receiver and 
operating slide. 

(9) Cammed surfaces in the hump of the 
operating slide. 

(10) Piston. 

(11) Magazine catch and magazine catch 

(12) Operating slide stop. 

e. Use rifle grease if the carbine is exposed to 
a great deal of rain or to spray from sea water, 
because the bolt may occasionally fail to open. 
This is caused by the friction resulting from the 
effect of the water and the fact that any ordinary 
lubricant is likely to be washed away from certain 
bearing surfaces. Under these conditions, it is 
essential that such surfaces be coated with rifle 
grease which resists the action of the water. Apply 
rifle grease to the parts shown in Figure 43b 
after wiping them clean and dry with a cloth. 
Rifle grease is not normally applied to other parts. 
After applying rifle grease, work the parts several 
times to spread the grease. 

f. Inspect the bolt to determine whether 
cracks have developed. Give special attention to 
the right hand locking lug and the area next to the 
firing pin hole. Bolts having visible cracks should 
be replaced. 


Before firing, take the following steps to 
make sure your carbine will function properly: 
a. Field-strip it. 


After you have fired, your main concern is 
to keep the carbine from becoming rusty. The 
deposit left after firing consists mainly of primer 
fouling, powder ashes, metal fouling, and carbon. 



Although carbine ammunition has a noncorrosive 
primer, it will leave a deposit when dried. Since 
this deposit might collect moisture and promote 
rust, it must be removed. Rifle bore cleaner re- 
moves this deposit and the powder ashes. Metal 
fouling is not common. It is removed only by 
ordnance personnel. 

a. Clean the bore of your carbine thoroughly, 
preferably right after firing, and certainly no later 
than the evening of the day you fire it. The bore 
is cleaned in the same manner for the next 3 days. 

(1) Use the following equipment: 
(a) M8 cleaning rod. 

(6) Rifle bore cleaner. 

(c) Patches. 

(d) Preservative lubricating oil. 

(e) Waste wipes. 

(2) Follow this procedure in cleaning the 

(a) Wet patches (rifle bore cleaner or 

warm soapy water). 
(6) Brush. 

(c) More wet patches. 

(d) Dry patches. 

■■■-■■.-. . . : 

**** im ****** * : « 

,■■ ... ..-..■ . 

■'■';■■ ■•■".■■'?• 
■ ■ ■ ■■'...■■■. 

;■ . . ;■■■-.■■;-:_ ■";;■;;' 

Figure 43b. Points on which to apply rifle grease. 

we< tut i». & >wt i h ftfcfr : 

■ ■ 

.. 4' uMa 

(e) Inspection. (Repeat the above until 
a dry patch comes out clean and no 
evidence of fouling can be seen in 
the bore.) 

(f) Oily patch. 

6. Additional cleaning of the chamber should 
not be necessary. The diameter of the chamber in 
the carbine is so nearly the same as that of the 
bore that the cleaning of the bore and chamber is 
accomplished simultaneously. 

c. Clean the piston nut by removing the 
carbon. Your organizational artificer will super- 
vise you when you remove the gas piston and 
piston nut of the gas cylinder group to clean 
them. Frequent removal of these parts causes 
excessive wear on the threads; therefore, these 
parts should be removed only when your carbine 
shows definite signs of insufficient gas. The lack 
of gas compression is indicated by failure to 
chamber or failure to extract a round. To remove 
the piston nut, clamp the barrel and receiver firmly 
in a vise with protected jaws and, using the gas 
piston nut removing tool, M5, unscrew the piston 
nut from the gas cylinder. When removing the 
piston nut be very careful not to burr or twist the 
prongs. To remove the piston, elevate the muzzle 
of the barrel and slide the piston nut out of the gas 
cylinder. If the piston will not slide out easily, 
tap the gas cyliner lightly with a wooden block. 
To remove the carbon from the piston and piston 
nut, use a cleaning patch saturated in rifle bore 
cleaner. Wipe off the excess with a dry patch and 
then apply a light coat of preservative lubricating 
oil. Be careful to align the threads when you re- 
place the piston nut so that you will not burr them 
as you tighten the nut. If you cannot easiiy thread 
the piston nut back into place, give the carbine to 
your supply officer to send to the proper ordnance 

d. Clean the face of the bolt with a patch and 
rifle bore cleaner. After cleaning, dry and oil 

e. Clean other metal parts and exterior 
surfaces with a dry cloth to remove dampness, dirt, 
and perspiration. Oil all metal parts with pre- 
servative lubricating oil. Oil the stock and hand 
guard with linseed oil. Rub it in well. 


a. There is no basic difference between the 
care of a carbine during range firing and during 
combat except — 



(1) The carbine may get much more severe 

(2) Conditions for maintenance may be 
much more difficult. 

(3) Issued materials for maintenance may 
be partially or completely lacking. 

£l Because of the above conditions and be- 
cause you have to keep your weapon in operating 
condition during combat, you must use your 
initiative, energy, and constant attention to over- 
come these difficulties. 

c. To obtain the maximum efficiency from 
your carbine, observe the following points: 

(1) Keep the bore and chamber clean. 
Do not fire the carbine when dirt, mud, 
snow, or any other obstruction is in 
the bore. Such obstructions are ex- 
tremely dangerous and may cause the 
barrel to swell or burst. Use a cleaning 
rod, if one is available, or the thong 
and brush which you should have. 
If these are not available, any slender 
rod or stiff wire can be used as a field 
expedient Using any one of these, 
keep the bore and chamber clean and 

lightly oiled. 

(2) Avoid excessive friction. If the carbine 
shows signs of excessive friction due to 
lack of lubrication, apply oil to the 
parts that need it. If this friction is 
the result of dirt and there is no time to 
clean the carbine, use an extra amount 
of oil in the places needed. Friction 
is indicated if the empty cartridge cases 
are being ejected to the right rear or if 
the action of the bolt is sluggish. Apply 
oil at the first opportunity, as failure 
to chamber and eject will occur if the 

condition is not corrected. 

(3) Use extra care under severe conditions. 
If the carbine is to be exposed to 
severe conditions of rain or salt water, 
apply rifle grease. The points on which 
to apply this grease are shown in Figure 

<£ Keep a thin coating of preservative lubri- 
cating oil on all metal parts. 

e. Remove the carbon from the head of the 
piston nut when necessary. 

£ In emergencies when the prescribed lubri- 
cants are not available, use any clean light mineral 

oil such as engine oil. 


Medium preservative lubricating oil is the 
most suitable oil for short term protection of the 
carbine mechanism. It is effective for storage over 
periods of 2 to 6 weeks, depending on climatic 
conditions. However, carbines in short term storage 
must be inspected every 4 or 5 days and the pre- 
servative films renewed if necessary. For longer 
periods of storage, carbines are protected with 
medium rust-preventive compound. Medium rust- 
preventive compound is a semi-solid material. It 
is efficient for preserving polished surfaces, the 
bore, and the chamber for a period of approx- 
imately 1 year, depending on climatic and storage 
conditions. The carbine must be cleaned and pre- 
pared for storage with particular care. The bore, 
all parts of the mechanism, and the exterior of 
the carbine should be thoroughly cleaned and then 
dried completely with rags. In damp climates, 
particular care must be taken to see that the rags 
are dry. After drying a metal part, the bare hands 
should not touch that part. All metal parts should 
then be coated with either medium preservative 

lubricating oil or medium rust-preventive com- 
pound, depending on the length of storage re- 
quired. The rust-preventive compound can best be 
applied to the bore of the carbine by dipping the 
cleaning brush into the compound and then run- 
ning it through the bore two or three times. The 
brush must be clean before it is used. Before 
placing the carbine in the packing chest, see that 
the bolt is in its forward position and that the 
hammer is released. Then, handling the carbine by 
the stock and hand guard only, place it in the 
packing chest whose wooden supports for the butt 
and muzzle have been painted with rust-preventive 
compound. Under no circumstances should a 
carbine be wrapped in a doth or other cover or be 
placed in storage with a plug in the bore. Such 
covers collect moisture and make the weapon rust, 


Carbines are received from storage with a 
coating of preservative lubricating oil or of rust- 
preventive compound. Carbines received from 
ordnance storage will usually be coated with rust- 
preventive compound. Use volatile-mineral-spirits- 
paint thinner or dry-cleaning solvent to remove all 
traces of the compound or oil. Take particular 
care that all recesses in which springs or plungers 
operate are cleaned thoroughly. Failure to do this 



may cause stoppages at normal temperatures and 
will certainly cause stoppages when the rust- 
preventive compound freezes during cold weather. 
After using the cleaning solvent, be sure it is 
completely removed from all parts by wiping with 
a dry cloth. Then apply a thin coat of preservative 
lubricating oil to all metal parts and use linseed 
oil on the wooden parts. 


a. If a chemical attack is expected or chemical 
contaminations are encountered, the following 
action should be taken: Apply oil to all outer 
metal surfaces of the carbine and accessories. Do 
not apply oil to ammunition. If the carbine is not 
to be used, cover it, the accessories, and the 
ammunition with protective coverings or disperse 
them under natural cover. Ammunition should be 
kept in its containers as long as possible. After a 
chemical attack, determine by means of detector 
paper (for liquid) or detector crayon (for vapors) 
whether or not the equipment is contaminated. 

b. If uncontaminated, clean the equipment 
with a dry-cleaning solvent. Prepare it for use as 

c. If contaminated, a complete suit of pro- 
tective clothing (permeable or impermeable), 
including impermeable protective gloves, and a gas 
mask must be worn during decontamination. 

(1) Equipment contaminated with chemi- 
cals other than the blister agents or 
G-series agents can be decontaminated 
by airing. For faster decontamination 
of this equipment and to protect 
against corrosion, clean the carbine 
and its equipment with rifle bore 
cleaner, denatured alcohol, or soap 
and water. 

(2) Equipment contaminated by blister 
agents will be decontaminated as 


(a) Remove dirt, dust, grease, and oil 

by wiping with rags. 

(b) Expose all surfaces to air. 

(c) Decontaminate all metal surfaces 
except the bore with agent, decon- 
taminating, noncorrosive (DANC) 
(FM 21-40). Hot water and soap, 
or repeated applications with gas- 
oline soaked swabs are also ef- 

(d) Protective ointment, M5, carried 
in the gas mask carrier, can be used 

for emergency decontamination 
(FM 21-40). 

(e) Test with detector paper or detector 
kit to see if decontamination is 


(f) After decontamination and tests are 
complete, clean, dry, oil, and pre- 
pare the carbine and its equipment 
for use as required. 

{g) Burn, or preferably bury, all rags or 
wiping materials used during de- 
contamination. Caution should be 
taken to protect men against vapors 
created by burning, 
(3) In general, these same actions are 
applicable to equipment contaminated 
by biological or radiological attack. 
If contamination is too great, it may be 
necessary to discard the equipment. 
Detailed information on decontam- 
ination is contained in FM 21-40 
and TM 3-220. 


a. In Cold Climates. In temperatures below 
freezing, the moving parts of your carbine must be 
kept absolutely free from moisture. Also, excess oil 
on the working parts will solidify to such an extent 
as to cause sluggish operating or complete failure. 

(1) The carbine should be disassembled and 
completely cleaned with volatile-min- 
eral-spirits-paint thinner or dry-cleaning 
solvent before use in temperatures 
below 32 degrees F, The working 
surfaces of parts which show signs of 
wear may be lubricated by rubbing 
with a cloth which has been wetted in 
special preservative lubricating oil; 
other parts are left dry. At temper- 
atures above 32 degrees F., all metal 
surfaces of the carbine may be oiled 
thinly, after cleaning, by wiping with a 
lightly oiled cloth using the medium 
preservative lubricating oil. 

(2) When brought indoors, the carbine 
should first be allowed to come to 
room temperature. Moisture will con- 
dense on the cold surfaces. Then dis- 
assemble the carbine and wipe it 
completely dry. Oil with the special 
preservative lubricating oil. This con- 
densation may be avoided by providing 



a cold place in which to keep the car- 
bine when not in use. For example, a 
separate cold room with carbine racks 
may be used, or, when in the field, 
racks under proper cover may be 
improvised. If the carbine has been 
fired, it should be cleaned and oiled. 
When the carbine reaches room temper- 
ature it should be cleaned and oiled 

b. Hot, Humid Climates. In tropical climates 
where temperature and humidity are high, or 
where salt air is present, and during rainy seasons, 
your carbine should be inspected thoroughly every 
day. It should be kept lightly oiled when not in 
use. The carbine should be field stripped at regular 
intervals and if necessary, should be disassembled 
enough to permit the drying and oiling of all 
parts. Care should be taken to see that unexposed 
parts and surfaces are kept clean and oiled. 
Medium preservative lubricating oil should be 
used. Wood parts should be inspected to see that 
swelling caused by moisture does not bind working 
parts. If swelling has occurred, shave off the wood 
only enough to relieve binding. A light coat of raw 
linseed oil applied at intervals and rubbed in with 
the heel of the hand will help to keep moisture 
out. Allow the oil to soak in for a few hours and 
then wipe and polish the wood with a dry clean 
rag. Care should be taken that linseed oil does not 
get on the working parts, because linseed oil thick- 
ens when dry. Stock and hand guards should be 
dismounted while this oil is being applied. 

c. Hot, Dry Climates. In hot, dry climates 
where sand and dust are likely to get into the 
mechanism and bore, the carbine should be wiped 
clean daily or oftener. Groups should be separated 
and disassembled for thorough cleaning. When the 
carbine is being used under sandy conditions, all 
lubricants should be wiped from the weapon. This 
will prevent sand from sticking to the lubricant and 
forming an abrasion which will ruin the mech- 
anism. Upon leaving sandy terrain, the carbine 
should be cleaned and relubricated . In such cli- 
mates, the wood parts are likely to dry out and 
shrink. A light application of raw linseed oil will 
help to keep the wood in condition. Since per- 
spiration from the hands contains acid and causes 
rust, it should be wiped from all metal parts. 
During sand or dust storms, the receiver and 
muzzle should be kept covered if possible. 



Some parts of your carbine may in time 
become unserviceable through breakage or wear 
resulting from continuous use. Extra parts are 
provided with the carbine to replace those parts 
most likely to fail. These parts normally will be 
kept with the organizational property. They should 
be kept cleaned and lightly oiled to prevent rust. 
Sets of spare parts should be kept complete at all 
times. Whenever a spare part is used to replace a 
defective part in the carbine, the defective part 
should be repaired or replaced. Parts that are 
carried complete should be correctly assembled 
and ready for immediate use with the carbine. 
The allowances of spare parts are prescribed in 
Ord 7 SNL B-28. Except for replacements with the 
spare parts mentioned above, repairs or alterations 
to the carbine are made only by ordnance person- 


The bayonet knife is a blade sharpened along 
the entire lower edge and partially along the upper 
edge. It is made to fit securely into the scabbard 
or onto the forward end of the carbine. A hand 
grip on its base makes it a suitable hand weapon 
or utility tool. 


Accessories include the tools required to 
assemble and clean your carbine, and the gun sling, 
spare parts containers, covers, arm lockers, and 
similar articles. They should be used for no other 
purpose than that for which they are intended. 
When not in use, they should be stored in the 
places provided for them. Detailed descriptions or 
methods for the use of all such accessories are not 
outlined in this manual. However, some of the 
most common accessories are described below. 

a. The brush and thong are used for cleaning 
the bore of the carbine when the cleaning rod 

is not available. 

b. The cleaning rod M8 is of such length as 
to prevent damage to the follower or the face of 
the bolt. The rod has a handle at one end and is 
threaded at the other end to receive the patch or 
brush sections. The patch section is slotted to per- 
mit the insertion of a cleaning patch; the brush 
section is used to clean the bore of the carbine 



after firing. The cleaning rod is provided with a 
web case for carrying purposes, 

a The oiler ; complete with cap and rod, 
contains oil for lubricating the carbine when the 
normal supply of oil is not available. The oiler also 
serves at the lower sling swivel. 

d. The sling Ml is placed on your carbine as 
shown in Figures 1 to 3 inclusive. The carbine sling 
is used for carrying purposes only. 



The ammunition that you may use in the 
carbine is described in this section. Your carbine 
can fire several types of ammunition. You are 
responsible for being able to recognize these types, 
for knowing which is best to use for certain targets, 
and for taking proper care of the ammunition. 

a In most type of small-arms ammunition, 
a cartridge consists of a cartridge case, primer, 
propelling charge, and the bullet. 

b. The term bullet refers only to a small arms 
projectile- The term ball was originally used to 
describe the ball shaped bullet of very early small 
arms ammunition* The term ball ammunition now 
refers to a cartridge having a bullet which has a 
metallic jacket filled only with lead, 


Based on use, the principal classifications of 

the several types of ammunition used with your 

carbine are — 

<z. Ball, Ml — for use in markmanship training 
and combat. 

& Tracer, M16 and M27 — observation of fire, 
incendiary, and signaling purposes. 

c. Dummy, M13 — for training (cartridges 
are inert). 


When ammunition is manufactured, it is given 
an ammunition lot number. This lot number is 
marked on all packing containers. It is also on the 
identification card inclosed in each packing box. 
The lot number is required for all purposes of 
record, such as grading and use, and reports on the 
condition, functioning, and accidents in which the 
ammunition might be involved. It is impracticable 
to mark the ammunition lot number on each 
individual cartridge. Every effort should be made 
to maintain the ammunition lot number or the 

repacked lot number with the cartridges after they 
are removed from their original packing. Cartridges 
which have been removed from their original 
packing for which the ammunition lot number has 
been lost are automatically placed in grade 3; 
these are not to be fired. 


a. Markings, The contents of original boxes 
may be readily identified by the markings on the 

box. Similar markings on the cardboard carton 
label identify the contents of each carton. The 
markings which appear on the box and carton 
give complete information necessary for identi- 
fication, shipping, care, handling, and use. 

b. Identification of Ammunition Types. 
In general, all types of cartridges of one caliber 
look alike in shape and size, but they may be 
identified by certain physical characteristics. The 
ammunition authorized for use with the carbine 
and the way to identify each type after it has been 
removed from the original container follows: 

Types of 





All models of caliber .30 ball am- 
munition have bullets coated with 
gilding metal, a copper alloy, which 
prevents fouling in the bore of the 
rifle. Ball ammunition has no iden- 
tifying color on the tip of the bullet. 
Tip of the bullet is painted red or 

The cartridge is inert and has three 
holes in the case. 


Most men have at one time or another fired a 
rifle or a pistol, or perhaps both types of weapons. 
If you have, it means you have also handled 
ammunition for these weapons. You know that the 
ammunition was not dangerous to handle. This, 
of course, does not mean that you handled the 
ammunition carelessly. The ammunition used in 
your carbine is not dangerous to handle, but there 
is a correct way to handle it. 

a Try to prevent ammunition boxes from 
becoming broken or damaged. All broken am- 
munition boxes must be repaired immediately* 
All original markings must be transferred to the 
new parts of the box. The metal liner should be 



air tested and sealed if equipment for this work is 

b. Open wooden ammunition boxes care- 
fully. They are used as long as they are service- 

c. Do not open ammunition boxes until the 
ammunition is to be used. Ammunition removed 
from the airtight container, particularly in damp 
climates, is likely to corrode. This ammunition is 

d. Protect ammunition from mud, sand, and 
water. If it gets wet or dirty, wipe it off at once 
with a clean, dry cloth. A light corrosion should 
be wiped off as soon as it is discovered. Car- 
tridges with a heavy coat of corrosion must be 
turned in. 

e. During markmanship and combat training, 
do not fire any caliber .30 carbine ammunition 
until it has been identified by an ammunition lot 
number and grade. 

f. Do not expose ammunition to the direct 
rays of the sun. If the powder is heated, excessive 
pressure may be developed when the weapon is 
fired. This condition will affect ammunition 

g. Do not oil or grease ammunition. The dust 
and other abrasives that collect on greasy am- 
munition are harmful to the operating parts of the 

ft. Do not attempt to fire cartridges that have 
bad dents, scratches, or loose bullets, or those that 
are rusted. If you think a cartridge is defective, 
return it. Do not throw away or attempt to destroy 
defective ammunition. 

i Be especially careful not to strike the 
primer of a cartridge since this may ignite the 


a. Small-arms ammunition is not an explosive 
hazard. Under poor storage conditions, however, it 
may become a fire hazard. 

b. Small-arns ammunition of all classes should 
be stored away from radiators, hot water pipes, 
and other sources of heat. 

c. Whenever practicable, small-arms am- 
munition should be stored under cover. If it is 
necessary to leave ammunition in the open, it 
should be raised at least six inches from the ground 
and covered with a double thickness of tarpaulin. 
The tarpaulin should be placed so that it gives 
maximum protection and allows free circulation 
of air. Suitable trenches must be dug to prevent 
water from flowing under the ammunition pile. 


The approximate maximum range and average 
muzzle velocity of the different types of caliber 
.30 carbine ammunition authorized for use in the 
carbine are shown below. 


Ball, M 1 
Tracer, Ml 6 
Tracer, M27 

Max. range 

1 r 680 

Average muzzle 





The general precautions concerning the firing 
and handling of ammunition in the field as pre- 
scribed in SR 385-310-1 and in TM 9-1900 will be 
observed. Precautions particularly applicable to 
small-arms ammunition are given in the following 


a. No small-arms ammunition will be fired 
until it has been positively identified by ammu- 
nition lot number and grade. 

b. Small-arms ammunition graded and marked 
for training use only will not be fired over the 
heads of troops under any circumstances. 

c. Before firing, be sure that the bore of your 
weapon is free from any foreign matter such as 
cleaning patches, mud, sand, snow, and the like. 
Any obstruction in the bore will damage the 
weapon and may injure you. 

d. When a bullet lodges in the bore of a car- 
bine, you should remove it by applying pressure 
from the muzzle end of the weapon. To attempt to 
shoot the bullet out with another cartridge is dan- 
gerous and is prohibited. 


When a hangfire (a perceptible delay between 
the blow of the hammer and the firing of the 
round) occurs, further use of ammunition from 
that lot should be suspended and a report made to 
the post ordnance officer, giving the lot number 
involved. The lot affected will be withdrawn and 
replaced by serviceable ammunition. 


IV. Inspection 



This chapter provides specific instructions for 
the technical inspection by ordnance maintenance 
personnel of materiel either in the hands of troops 
or when received for repair in ordnance shops. It 
also briefly describes the in-process inspection of 
materiel during repair or rebuild and the final 
inspection after repair or rebuild has been com- 
pleted. Trouble shooting information is incor- 
porated wherever applicable as a normal phase of 


Inspections are made for the purposes of 
(1) determination of the condition of an item as 
to serviceability, (2) determination of incipient 
failure, (3) the assurance of proper application of 
maintenance policies at prescribed levels, and 
(4) the ability of a unit to accomplish its main- 
tenance and supply missions. 


In general, five categories of inspection are 
performed by ordnance maintenance personnel. 

a. Over-all Inspection. This is a periodic over- 
all inspection performed by a contact party on 
materiel in the hands of troops and an inspection 
performed by maintenance company personnel 
when materiel is evacuated to the ordnance com- 
pany. The inspection of materiel evacuated is more 
thorough and includes check and repair of minor 

points that would not be required in the inspection 
performed by a contact party. 

b. Pre-embarkation Inspection. This inspec- 
tion is conducted on materiel in alerted units 
scheduled for oversea duty to insure that such 
materiel will not become unserviceable or worn 
out in a relatively short time. It prescribes a higher 
percentage of remaining usable life in serviceable 
materiel to meet a specific need beyond minimum 


c In-process Inspections. These are inspec- 
tions performed in the process of repairing (field 
mainte nance) or rebuilding (depot maintenance) 
the materiel as prescribed in Chapter 4. This is 
to insure that all parts conform to the prescribed 
standards, that the workmanship is in accordance 
with approved methods and procedures, and that 
deficiencies are disclosed by the preliminary 
inspection are found and corrected. Detailed 
instructions are contained in Chapter 4. 

d Final Inspection, This is an acceptance 
inspection performed by a final inspector, after 
repair or rebuild has been completed, to insure that 
the materiel is acceptable for return to user or for 
return to stock according to the standards es- 
tablished- Detailed instructions are contained in 
Chapter 5. 

e. Spot Check Inspection. This is a periodic 
over-all inspection performed on only a percentage 
of the materiel in each unit to determine the 
adequacy and effectiveness of organizational and 
field maintenance- 





Warning: Before starting a technical inspec- 
tion, be sure to clear the weapon. Do not touch the 
trigger until the weapon has been cleared. Inspect 
the chamber to insure that it is empty and check 
to see that no ammunition is in position to be 
introduced. Avoid having live ammunition in the 

vicinity of the work. 

a. Preparatory Procedures. 

(1) Check to see that the weapon has been 
cleaned of all corrosion-preventive 
compound, grease, excessive oil, dirt, 
or foreign matter which might inter- 
fere with proper functioning or obscure 
the true condition of the parts. 

(2) Make an overall inspection of the 
weapon for general appearance, con- 
dition, operating, and manual func- 
tioning. Use dummy cartridges. 

b Inspection Guide. Table II is provided as 
a check list to be used as a guide for the inspection 
of weapons in the hands of troops. The over-all 
inspection column lists the standards denoting 
minimum serviceability and next column lists 
the standards for pre-embarkation inspection. 

Note. The additional columns are provided 
for comparative information only to show the 
standards which are desired when the weapon is 
repaired or rebuilt in ordnance field or depot 


a. General. Refer to TM 9-1100 foi respon- 
sibilities and fundamental duties of inspecting 
personnel, the necessary notice and preparations to 
be made, forms to be used, and general procedures 
and methods to be followed by inspectors. Materiel 
to be inspected includes organizational spare parts 
and equipment and the stocks of cleaning and 
preserving materials. In the course of this technical 
inspection the inspector will accomplish the 


(1) Determine serviceability, i.e., the degree 
of serviceability, completeness, and 
readiness for immediate use, with 
special reference to safe and proper 
functioning of the materiel. If the 
materiel is found serviceable, it will be 
continued in service. In the event it is 

found unserviceable or incipient fail- 
ures or disclosed, the deficiencies will 
be corrected on the spot or advice 
given as to corrective measures when 
applicable, or if necessary, the materiel 
will be tagged for delivery to and repair 
by ordnance maintenance personnel. 

(2) Check for causes of mechanical and 
functional difficulties that troops may 
be experiencing and for apparent 
results of lack of knowledge, mis- 
information, neglect, improper han- 
dling and storage, security, or preser- 

(3) Check on application of all authorized 
modifications to see that no unauthor- 
ized alterations have been made or that 
no work beyond the authorised scope 
of the unit is being attempted. The 
following modification work orders are 
considered mandatory as of this print- 
ing; however, also check the index 
in SR 310-20-4 and the current modi- 
fication work order files for any 
additional modification work orders 
promulgated subsequent to this print- 








Replacement of leaf type 
rear sight with adjustable 
rear sight. 

Replacement of magazine 
catch and plungeT to provide 

increased holding. 
Replacement of front band 
to provide for attachment of 


Replacement of sliding type 

safety with rotary type. 
Replacement of disconnector 
plunger assembly to prevent 
its loss. 

(4) Instruct the using personnel in proper 
preventive maintenance procedures if 
and where found inadequate. 

{5) Check on completeness of the organi- 
zational maintenance allowances and 
procedures for obtaining replenish- 


Table II. Inspection Guide for Cal. .30 Carbines Ml, M1A1, M2, and M3 

Point To Be Inspected 







Overall Inspection 



Final Inspection, 
Field Maintenance 

Final Inspection, 
Depot Maintenance 

Pits in chamber are allowable if they are not large enough to cause extraction 
difficulties. Pits in the bore as wide as a land or groove and three-eights inch, or 
less, in length are allowable. Tool marks or scratches are acceptable regardless of 
length. Tool marks will appear as lines rujning laterally in the grooves or may 
run spirally across top of lands. Definitely ringed bores or bores ringed suffi- 
ciently to bulge the outside surface of the barrel must be rejected. However, 
faint rings or shadowy depressions are acceptable. Lands must be sharp. 

Some glare per- 
No check. 

Apply MWO ORD 
B28-W5 if not 
Securely assembled 
with no burrs or 
Not damaged so as 
to affect strength. 
Some looseness 
when assembled 

is acceptable. 
Liner must be 

Intact enough to 

prevent glare. 

No check. 

Apply MWO ORD 

B28-W5 if not 

Securely assembled 

with no burrs or 

Checks and cracks 
not affecting 
strength are ac- 
ceptable. Some 
looseness when 

assembled is ac- 
ceptable. Liner 

must be tight. 

Intact enough to 

prevent glare. 


Apply MWO ORD 

B28-W5 if not 
Securely assembled 
with no burrs or 
Checks and cracks 
not affecting 
strength are ac- 
ceptable. Some 
looseness when 
assembled is ac- 
ceptable. Liner 

must be tight. 

Approximate new 


Min. 0.048. 

Max. 0.065. 

Apply MWO ORD 

B28-W5 if not 

Securely assembled 

with no burrs or 
Seasoned checks 
and cracks which 
have been rein- 
forced by pins are 
acceptable. Some 
looseness when as- 
sembled is accept- 
able. Liner must be 






Table II continued. 

-^ff^h Ad ■ K 


Final Inspection, 

Final Inspection. ! 

Point To Be inspected 

Overall Inspection 


Field Maintenance 

Depot Maintenance 



Bolt must not close 

Bolt must not close 

Min. 1.290 

Min. 1.290 

on headspace gage 

on headspace gage 

Max. 1.302 

Max. 1.295 

7319943 (head- 

7319943 (head 

Use gage 7319934 

Use gage 7319934 

space Igh. 1.302) 

space Igh. 1.302) 

or 7319943. 

or 7319936. With 

but must close 

but must close 

field test bolt 

without forcing 

without forcing 

7329936. With field 

on headspace gage 

on headspace gage 

test bolt 7319932. 

731 9934 (head- 

7319934 (head 

space Igh. 1.290). 

space Igh. 1.290). 

Not Rebarreled 

Min. 1.290 
Max. 1.298 
Use gage 7319934 

or 7319938. 






Table It continued. 

Point To Be 1 nspected 

Overall Inspection 


Final Inspection, 
Field Maint. 

Final Inspection, 
Depot Maint. 

Mot Rebarreled 


Magazine catch is 

Magazine catch is 

Magazine catch is 

Magazine catch is 

to engage magazine 

to engage magazine 

to engage magazine 

to engage magazine 

with sufficient 

with sufficient 

with sufficient 

with sufficient force 

force to prevent 

force to prevent 

force to prevent 

to prevent removal 

removal of maga- 

removal of maga- 

removal of maga- 

of magazine with- 

zine without re- 

zine without re- 

zine without re- 

out releasing catch. 

leasing catch. Ap- 

leasing catch. Ap- 

leasing catch. Ap- 

Apply MWO ORD 

ply MWO ORD 

ply MWO ORD 

ply MWO ORD 

B28-W4 if not ac- 

B28-W4 if not ac- 

B28-W4 if not ac- 

B28-W4 if not ac- 

complished. Inspect 



complished. In- 
spect each as- 
sembly to assure 

each assembly to 
assu re th at the m aga- 
zine catch can be 

that the maga- 
zine catch can be 
pushed rearward in 
the trigger housing 
and that the safety 
plunger spring is 
strong enough to 

return it firmly to 

the forward posi- 
tion. The forward 
pressure on the 
magazine catch 
must not prevent 
proper sidewise 
travel of catch. 

pushed rearward in 
the trigger housing 
and that the safety 
plunger spring is 
strong enough to 
return it firmly to 
the forward posi- 
tion. The forward 
pressure on the 
magazine catch 
must not prevent 
proper sidewise tra- 
vel of catch. 




Table II continued. 

Point To Be Inspected 







Overall Inspection 

Elevation and 
windage slides 

to function 
smoothly through- 
out range. Gradua- 
tions to be legible. 
Apply MWO ORD 
B28-W3 if not ac- 

Apply MWO ORD 

B28-W6 if not ac- 
complished. Rotate 

safety to see that 
it functions prop- 

Not damaged to 
extent that it 
will affect 

Min. 4% lb. 
Max. 7 lb. 


E levation and 
windage slides 
to function 
smoothly through- 
out range. Gradua- 
tions to be legible. 
Apply MWO ORD 

B28 W3 if not ac- 

Apply MWO ORD 
B28-W6 if not ac- 
complished. Rotate 

safety to see that 
it functions prop- 
Seasoned checks, 

small dents and 


cracks are ac- 

Min. 4% lb. 
Max. 7 lb. 

Final Inspection 
Field Maint. 

Elevation and 
windage slides 
to function 
smoothly through- 
out range. Gradua- 
tions to be legible. 
Apply MWO ORD 
B28-W3 if not ac- 

Apply MWO ORD 
B28-W6 if not ac- 
complished. Rotate 
safety to see that 
it functions prop- 
Seasoned checks, 

small dents and 
cracks are ac- 

Min. 4% lb. 
Max. 7 lb. 

Final Inspection, 
Depot Maint. 

Elevation and 
windage slides 
to function 
smoothly through- 
out range. Grauda- 
tions to be legible. 
If necessary, refill 
windage markings 
with white gradu- 
ation filler. Apply 
if not accomplished. 
Apply MWO ORD 

B28-W6 if not ac- 
complished. Rotate 
safety to see that 
it functions prop- 
Approximate new 

stock. If necessary, 
sand and refinlsh • 
Patchwork not af- 
fecting strength is 
acceptable. Repair 
screws and wood 
dough acceptable. 

Min. 4% lb. 
Max. 7 lb. 






(6) Check conditions of storage of general 
supplies and ammunition. 

(7) Initiate a thorough report on materiel 
on "deadline," with reasons therefor, 
for further appropriate action. 

(8) The inspector should report to the 
responsible officer any carelessness, 
negligence, unauthorized modifications, 
or tampering. This report should he 
accompanied by recommendations for 
correcting the unsatisfactory condi- 

b. Insertion for Appearance and General 


(1) Inspect barrel and receiver group for 
looseness in stock, and hand guard for 
excessive looseness on stock. Hand 
guard may have slight movement back- 
ward and forward. However, there 
should be no possibility of its be* 
coming disengaged from the front band 
or skirt on the receiver. Tight hand 
guards are likely to push band off when 
recoil is heavy, as when grenade launch- 
er is used. 

(2) Inspect front band for looseness and 
locking on carbine and inspect sling 
swivel for looseness on band. Band 
should be held firmly in place by 
shoulder of locking spring. 

(3) Inspect stock and hand guard for 
cracks; deep scars; and bare, rough 
wood surface: check grip (M1A1) 
for looseness in stock and for cracks* 

(4) Inspect front and rear sights for loose- 

(5) Inspect oiler for retention in stock and 

for new type neoprene gasket. Inspect 
sling for wear and security on carbine. 

(6) Inspect metal parts for rust, corrosion, 
scoring, and cracks. 

(7) Inspect magazine for retention in 
trigger housing, ease of withdrawal, 
undue looseness, dents, rust, and move- 
ment of follower. 

(8) Inspect sling eyelet for looseness on 
lower hinger assembly (M1A1), and 
hinge for looseness on stock grip. 

(9) Inspect stock extension (M1A1) for 
hinge action, and positive locking when 
extended and folded, and butt plate 
for rotation and spring action on bars. 

(10) Inspect cheek rest plate and retaining 
plate (M1A1) for looseness on bars, 

and cheek rest plate cover for wrinkles, 
scoring, and dried out leather. 

(11) Inspect barrel. 

(12) Check to see that serial numbers on 
the receivers of Ml and M1A1 carbines 
(Fig. 87) have not been obscured by 
the installation of the adjustable rear 
sight 7160060 (stamped type), 

c. Functional and Opera tio nal Inspect io n . 
The following are in addition to inspections 
covered on page 31* 

(1) Complete locking of bolt and forward 
movement of operating slide. The slide 
should continue to move forward about 
five-sixteenth of an inch after the bolt 
is fully locked. The same free move- 
ment should take place at the start of 
the rearward movement of the slide, 
before rotation of the bolt begins. 

(2) Chambering of cartridge. The bolt 
should chamber the cartridge smoothly 
when released. If bullet ramp on re- 
ceiver or barrel is rough, or if magazine 
catch does not retain magazine allow- 
ing it to tip forward, the bullet may 
bind on ramp or be deflected upward 
during chambering and strike the top 
of the barrel causing a stoppage. 

(3) Engagement of sear when trigger is 
not released. On carbines Ml and 
M1A1 and on carbines M2 and M3 in 
semi-automatic position, the sear should 
engage and hold the hammer when the 
trigger is held back and the slide op- 
erated rapidly. This can be tested for 
by the following procedure: 

(a) Grasp carbine by grip of stock with 
left hand. 

{b) With index finger of left hand, 
pull trigger all the way to the rear 
and hold it in that position. 

{c) Grasp operating slide handle with 
the right hand and move bolt back 
and forth rapidly five or six times, 
allowing the operating slide to 
come to rest in its forward position. 

id) Release trigger completely and then 
pull it again. If the hammer does 
not fall, it has been jarred out of 
engagement with the sear and 
followed the bolt forward. If this is 
the case, the carbine may fire in an 
uncontrolled manner and the firing 



mechanism must be inspected for 
worn or faulty parts. 

(4) Uncontrolled fire. It has been found 
that at times individual carbines Ml 
and M1A1 fire in an uncontrolled 
manner. The term "uncontrolled" 
means that more than one cartridge 
is chambered and fired when the trigger 
is actuated once. Since the carbines Ml 
and M1A1 are both semi-automatic 
weapons, only one round should be 
fired whether the trigger is held or 
released. This tendency can often be 
determined during firing by the follow- 
ing procedure: 

(a) Hold trigger in rearmost position. 

(b) Manually retract the operating slide 
and allow it to return to battery. 

(c) Release trigger very slowly. If 
carbine tends to fire in an un- 
controlled manner, the hammer will 
often fall when the sear is heard to 
snap. The shock of counterrecoil 
will sometimes jar hammer from 
seal- and uncontrolled fire results. 

(5) Safety. The safety should rotate with- 
out undue interference. It should 
block trigger when turned so that the 
tang is vertical and release trigger when 
tang is pointing to the rear. It should be 
positively retained in either position. 

(6) Operating slide stop. The operating 
slide stop is for the purpose of "hang- 
ing" the slide and bolt in the retracted 
position. Test functioning of stop by 
retracting bolt with operating slide, 
spring, and guide assembled, and 
pressing stop into retaining notch in 
receiver. When "hung" slide is slightly 
retracted, the stop should be cammed 
out of retaining notch in receiver and 
lie flush with (or above) lower face of 
slide and be held in this position by 
the friction spring. If stop spring 
becomes broken, stop may catch in 
retaining notch when slide reciprocates. 
If nose of stop or edge of retaining 
notch ecomes worn, or friction spring 
becomes weak or broken, stop is likely 
to slip and fail to hang bolt. If there 
is insufficient friction on stop, it may 
jar into the notch and "hang" the bolt 
when the carbine functions. If such is 

the case, replace stop, spring, or oper- 
ating slide. 
d. Magazine. Test magazine for retention in 
carbine. Inspect foUower for smooth movement in 
tube under force of spring by depressing follow- 
er and allowing it to rise. If follower does not 
depress and rise smoothly to the top of tube 
under spring action, look for burrs, rust, and 
corrosion in tube, reversed follower, deformed, or 
burred tube or follower, and weak, broken or 
reversed spring. Apply pressure evenly on the 
follower when depressing in order not to "cock" 

or rotate it in the tube. 

e. Rear Sight Assembly. See page 75 for 

inspection of the rear sight assembly. 

f. Barrel and Receiver Group. See page 80 
for inspection of the barrel and receiver group. 

g. Head Space Gaging. 

(1) The head space of a carbine is the 
distance between the shoulder of the 
chamber and the face of the bolt when 
the bolt is in locked position. If head 
space is insufficient, the bolt will not 
fully lock behind the cartridge without 
being forced. If head space is excessive, 
the cartridge will have too much play 
in the chamber when the bolt is locked 
behind it. Either condition is unsafe. 
As component parts of the carbine are 
manufactured to close tolerances and 
head space is carefully checked at 
manufacture, any variation causing 
excessive head space to develop is due 

to wear. 

(2) Excessive head space, due to wear, may 
be caused by worn faces of bolt, worn 
locking lugs on bolt, or worn locking 
shoulders in the receiver. 

(3) Before testing for head space, clean 
bore, chamber of barrel, and operating 
parts thoroughly, wipe dry, and inspect 
for metal fouling or foreign matter. 
Operate the mechanism a few times to 
see that the bolt closes and locks 
smoothly on an empty chamber. 
Disengage the bolt from the operating 

(4) See page 82 for procedure in checking 

head space. 

h. Trigger Pull 

(1) General The testing of trigger pull of 
carbines requires the availability of 
hooks and weights, which combine to 
4^ and 7 pounds. Test trigger pull for 



smoothness and for pressure exerted. 
Trigger pull should be clean, without 
creep, smooth in action; and the force 
exerted to release hammer should be 
more than 4 l A pounds and less than 7 
pounds. If pull is rough, or not within 
specified limits, or creep is present, 
it indicates that there is wear or burrs 
on sear nose, hammer notch, or top of 
trigger lip, or interference between 
trigger and housing. 

Note. The word "creep" is interpreted 
to mean any perceptible movement in 
the trigger pull between the time the 
slack is taken up and the hammer is 
released, with pressure applied to the 
trigger at a uniform rate of increase 
over a period of 10 seconds or more. 

(2) Testing trigger pull (Fig. 43c). Note 
that safety is disengaged (its tang is 
point to rear) and that carbine is 
cocked. Have the weights resting on the 
floor or ground and insert the hook of 
trigger weight wire through the trigger 
housing guard bow to bear on the 
trigger so that pressure is applied 
one-quarter inch from lower end or 
tip of trigger. With the barrel of the 
carbine held vertically, raise the weight 
from the floor as gently as possible. 
If 416-pound weight pulls the trigger 
to release the hammer, or the 7-pound 
weight fails to pull the trigger to 
release the hammer, correction is 
required. The only correction allowed 
in field repair is the selective assembly 
of hammer, hammer spring, sear, 
or trigger or all four until the required 
pull is obtained. Take care during the 
test to see that the wire contacts the 
trigger only and does not rub against 
the trigger housing or stock, and that 
wire and axis of bore are perpendicular 
to the floor. 

Note. Each time weights are applied 
to the trigger, cock the weapon again, 
otherwise sear may be partially dis- 
engaged from hammer. This will 
result in a false reading next time 
weights are applied. 

j. Inspection of Functions Peculiar to Car- 
bines M2 and M3. 

With carbine fully assembled, unloaded, and 
safety turned to fire position, test functioning as 


(1) Pull selector fully to rear to place 
mechanism in the semi-automatic po- 
sition. Then, with trigger released, 
fully retract- bolt to cock the hammer 
and allow bolt to spring forward. 
Hammer should not fall until trigger 
is pulled. 


wK 1 


HA PO 9.4J* 

Figure 43c, Testing trigger pull. 



Table ill. Trouble Shooting 


Failure to eject. 

Failure to extract. 

Trigger hang. 

ilure to fire. 

Hammer fails to cock 

Light trigger pull 
Safety sticks. 

Operating slide does not 
operate smoothly or 
does not "hang". 
Obscured serial number. 

Probable Causes 

Broken ejector. 

Weak or broken ejector 


Damaged or broken 

extractor claw. 

Broken or missing 

extractor plunger or 


Large pits in firing 


Weak, bent, or broken 

trigger spring. 

Trigger spring disengaged. 

Old type trigger with 

4- or 8-degree angle on 

forward face of the 

Defective ot broken 

firing pin. 

Damaged sear or broken 

sear spring. 

Failure of bolt to move 
far enough to rear. 
Weak or broken sear 


Missing or broken safety 

plunger and/or spring. 

Damaged safety. 

Broken stop and /or spring. 

Misalignment of barrel 

in receiver. 

Installation of rear sight 

7160060 on receivers of 

carbines M1 and M1A1. 

Also M2 carbines converted 

from M1 carbines. 

Corrective Action 

Replace ejector. 
Replace spring. 

Replace extractor. 

Replace plunger and /or 

Replace barrel. 

Replace trigger spring. 

Check seating of spring in 
seating notch in trigger 
and position of spring 
in housing aperture. 
Replace with trigger of 

new design. 

Replace firing pin. 

Replace sear and /or spring. 

Check guideways in receiver 
for obstruction to movement 
Replace sear spring. 

Replace safety plunger 
and /or spring. 

Replace safety. 
Replace stop and /or spring. 
Check parallelism of barrel 
and receiver and correct. 
Restamp serial number. 



(2) With trigger held back, cock the ham- 
mer as above and allow bolt to spring 
forward. Hammer should not fall 
until trigger is released and then pulled. 

(3) With trigger released, retract bolt to 
cock hammer and allow bolt to spring 
forward. Push selector forward to place 
mechanism in full automatic position. 
Hammer should not fall until trigger 
is pulled* 

(4) With selector still forward, and trigger 
held back, retract bolt to cock hammer, 
then ease bolt forward slowly. The 
hammer should not fall until the bolt 
is fully locked • The hammer can 
distinctly be heard striking the firing 

(5) Test safety with selector in both 
positions- It should not be possible 
to release the hammer with safety tang 



The inspection of the weapon received in 
ordnance shops is essentially the same as its in- 
spection in the hands of troops (Page 44)- Table 

III lists malfunctions, possible causes, and actions 
required to correct the malfunction. 



a. See table II for pre-embarkation inspection 
of cal. .30 carbines. 

6. AU URGENT Department of the Army 
modification work orders will be applied before 
approving the materiel for oversea shipment. 

c. Certain small arms are manufactured with 
a neutral gray finish. Phosphate finish ranges from 
neutral gray to black and is acceptable within this 
color range. Rejection because of improper finish 
must be only on the grounds that the exterior 
surface has a distinct shine and is capable of 
reflecting light, somewhat as a mirror does. 

& Scratches and tool marks on barrel are 
ordinarily of no importance. 


V. Repair & Rebuild 




a. Information and instructions contained 
herein are supplementary to instructions for the 
using organization contained in FM 23-7. 

& In this manual, the main groups of the 
weapon are disassembled, inspected, replaced or 
repaired, and assembled. For information on 
removal and installation of groups, see page 13. 
A group is a number of parts or assemblies, or 
both, which either function together or are in- 
timately related to each other and should be 
considered together (Fig. 43d). 

a A rebuilt flow chart (Fig. 44) and an 
operation route sheet (Table IV), which specify 
the various steps necessary in rebuilding the 
weapon, are contained in this chapter for the use 
of maintenance shops engaged in rebuild for return 
to stock. 

d. Information for ordnance maintenance 
units engaged in repair for return to user and 
information for maintenance shops engaged in 
rebuild for return to stock are covered together, 
but wherever the operation is not authorized for 
the field level of maintenance, a note is added such 
as (DEPOT MAINTENANCE ONLY) to indicate 
the prescribed level of maintenance. 

e. Where different standards or tolerances 
are prescribed for field and for depot levels, the 
desired standard for the particular level is similarly 
indicated in parentheses. 

Degrease, clean, and oil all materiel received 
in ordnance shop. Keep a light film of oil on all 
parts undergoing rebuild operations to prevent 
rust from forming on surfaces. Processed materiel 
in the shop should be kept clean and oiled at all 
times to prevent rusting. Information and in- 
structions pertaining to cleaning, preserving, 
sealing, and related materials, are contained in 
TM 9-850. For detailed instructions for care and 

cleaning of the carbine, see page 32. 


a. The foreman in charge of repair and rebuild 
will procure a complete set of special tools. The 
number of units to be processed will determine the 
disposition of manpower and job procedure, and 
the extent to which improvised tooling, assembly 
line methods, and special shop provisions are 


£>. Precision tools for inspection of critical 
dimensions and tolerances will be provided where 

c. Use only tools that fit snugly as loose 
fitting tools may damage part. 

d. It is the responsibility of personnel engaged 
in disassembly to inspect parts as they are re- 
moved. Irreparable parts should be dropped from 
flow of parts as soon as possible > 



e. Parts damaged to the extent that the cost 
of repair is greater than their replacement cost, 
should be discarded. 


a. Light rust may generally he removed with a 
cloth moistened with preservative lubricating oil 
or rifle-bore cleaner. If this does not suffice, use 
crocus cloth or fine abrasive cloth. Take care not 
to scratch or alter cleaned surfaces, to remove 
thoroughly all dirt and abrasive, and to reoil 
surfaces before assembling the parts. 

h. For removal of deposits caused by the acid 
reaction of the fingerprint on the metal of un- 
painted machined surfaces, use fingerprint remover 
oil 14-C-7 89-25. 


a. During the life of the carbine, polishing 
and stoning are necessary to relieve friction and to 
remove burrs set up by firing and usage. Remove 
burrs on screw heads, threads, and like surfaces 
with a fine file, or chase out with a corresponding 
sized die or tap. Remove burrs on working 
surfaces, such as bolt lugs, operating slide grooves, 
etc, with a fine grain sharpending stone. Smooth 
rounded contacting surfaces with crocus cloth. 

Caution: Be careful to stone and file evenly 
and lightly and do not remove more metal than is 
absolutely necessary. Never alter parts or assem- 
blies in any way that will affect interchange ability 
or proper operation or function. If parts are so 
damaged that critical dimensions would be changed 
by filing or stoning, replace with a part from stock. 

b. On wooden components, dents or muti- 
lations that do not affect strength or general 
appearance may be sanded out. Wood dough may 
be used if practicable. Unvarnished wooden com- 
ponents, such as stocks and hand guards, should be 
sanded all over and treated with linseed oil, mixed 
with an approved fungicide if inspection reveals 
presence of fungus. Patching is permitted where 
strength is not affected. See page 93 for repairs 
and patching of wooden components. Points that 
bind may be relieved by filing or paring using a 
fine file or sharp flat blade. 


All springs that are corroded, set, weak, 
distorted, or fail to meet standards are to be 
replaced. Refer to TB ORD 366 for coil spring 



All carbines rebuilt must be stamped with the 
initials of the rebuilding establishment in the 
United States; weapons rebuilt by oversea depot 
shops are not to be stamped. Stamp the initials 
identifying the establishment rebuilding a carbine 
on the left side of the stock between the hand grip 
and the butt plate. If the weapon is subsequently 
rebuilt at another establishment, place the new 
identifying initials directly below those preceding. 
If the weapon is rebuilt at the same establishment 
as before, new initials need not be added- The 
establishments and the initials to be used are as 

Augusta Arsenal AA 

Benicia Arsenal BA 

Mt. Ranier Ordnance Depot MR 

Raritan Arsenal . . RA 

Red River Arsenal RRA 

Rock Island Arsenal RIA 

Springfield Armory SA 


a. Function Firing. Following repair or 
complete rebuild, fire each M2 and M3 carbine 
10 rounds full automatic and 10 rounds semi- 
automatic. Fire each Ml and M1A1 10 rounds 
semi-automatic. If carbines do not function satis- 
factorily, additional rounds are authorized. Func- 
tion firing is required, in field maintenance, only 
when adequate facilities are available. Quality 
controlled function firing may be used provided 
the number of weapons to be function fired is 
sufficient to warrant. 

b. Function Tests, Function tests should be 
shot from the shoulder or from a buck, spring 
loaded to simulate actual recoii conditions. A 
spring which allows the carbine to recoil approxi- 
mately one-half inch is acceptable. If function 
tests indicate a lack of power, improvement may 
be secured through the use of the counterbored 
type pistol nut 5196436 which permits longer 
travel of the piston. Thus nut differs from the 



plain typo in that it has a counterbored piston seat 
in the forward end approximately 0.030 inch deep 
(Fig. 43e). 

Warning: A semi-automatic or automatic 

weapon which functions satisfactorily in a test 
that allows no recoil, may not function at all 
when fired under field conditions because of 
insufficient power. It is important, therefore, that 
the function tests be conducted properly. This is 
particularly important in the case of carbines 
M2 and H3. 

10.Q3Q1N DEEP; 


Figure 43e. Piston nut 5196436- 




niditttertyfr -tmmrmtmt* 

GUASD. HAND, ASSY -6212601 
CfcWNES Ml, M1A>. MV. AND Mi! 


.CAWINH MJ AN© «S-0«Y!$ 






HQUSiNO «(OOtt. A&SV-6544005 .CARBINES Ml AN© MlAl .■ 

MAGArtNt- *MY < 1.5 BOUND -6312*03^ 

-CAR^NtS Ml. M1AI. .MS. AND M3f 

_;'-JWSy~55i7157 'CAMHN«Ml. 

.'■-.«©«, A3SY-n*l«4S 
STOCK, fOlOiNC. A$4?~6$4*0&6 

«A RD *304WA 

■ f *> , ... 

'■"■'. 'n ■■ 

Figure 43d. Assemblies comprising the weapon shown in relative positions. 




2 3 



4 5 










CAL .30 CARBINE Ml, HlAf r M2 r AND M3 





&. 7. a, % \o 



ALL KAitll 









13 r«u 20 
















30 31 



















RA PD 130491 

Figure 44. Rebuild flow chart. 














Table IV. Operations Route Sheet for cal. .30 Carbines Ml, M1 A1 r M2, and M3 



Check for live ammunition 


Record serial number 

Remove stock and hand guard 

Disassemble into subassemblies 

Disassemble trigger housing group 

Disassemble bolt 
Disassemble operating slide 

Remove gas cylinder pistol and nut if 


Remove front and /or rear sight if necessary 

Clean all parts 

Inspect stock and hand guard for dents, 

multilation and cracks 

Inspect trigger housing and components 

a. Inspect for wear. 

b. Check to see that new type hammer 
and spring are used for the carbines 

M1 andMIAI. 

c. Check to assure that rotary safety is 

used on all carbines. 

d. Check to see that new type magazine 

catch is used. 

e. Check to see that latest safety and 
magazine catch plunger assembly 
is used. 

Inspect operating slide group 

a. Inspect for wear and cracks of slide. 

b. Check to assure that new type stop 
and spring are used. 

c. Inspect slide spring and guide for 
rust, deformation and wear. 


Vapor degreasor 





















Table IV continued 










I nspect bolt 

a. Inspect for wear. 

b. Check to assure that new unused 
extractor, spring and plunger (new 

type) are used. 

c. Check for modified or new type 
firing pin. 

Inspect barrel and receiver 

a. Check for looseness and alignment. 

b. Inspect for wear and cracks in receiver, 

c. Inspect barrel and receiver for 

d. Inspect gas cylinder group. 

e. Check for obscured serial number. 

f. Check head space. 

Make replacement of parts and repairs 

as required 

Ref i rush as required 

Polish and refinish as required 


Ream chamber if necessary and check 

head space 

Sandblast for ref inishing if necessary 

Rebarrel if necessary and check head space 

Assemb I e s u bassem b J i es 




F ixtu res 













Gages as above 

Table IV continued. 











Assemble subassemblies to carbines 


Function fire 

Do necessary repairing 

Clean carbine 

Final inspection 

Record serial number (optional) 

Preserve and pack 


rt operations 26 & 27 if repair work is performed. 








a. Refer to page 14 for instructions on the 
removal and disassembly of the trigger housing 

b, To facilitate the removal and installation of 
the trigger spring (Fig. 45), tool 7160026 has been 
devised, to he used as follows: 

(1) Remove the stock from the carbine. 

(2) Insert the tube portion of the trigger 
spring removing tool (Fig. 46) in the 
recess in the rear of the trigger housing 
containing the trigger spring; compress 
and retain the trigger spring within the 
tube of the tool. 

(3) Turn the handle of the tool one- 
quarter turn counterclockwise. 

(4) Withdraw the tool and spring while 
pushing the handle of the tool slightly 
to the right. 


a. General. Inspect all parts for damage, 
excessive wear which might cause malfunction, 

burrs, rust, foreign matter in recesses, deformation, 
and free action with mating parts. 

b. Trigger Housing (Figs. 45 and 47). Inspect 
housing for deformation, worn (elongated) or 
burred pinholes, wom or burred retaining lugs, 
bent trigger guard bow, foreign matter in recesses, 
burred magazine catch guideway, and rust. Some 
of the fabricated (brazed) type of housings were 
cyanide hardened during manufacture and some 
were not. The pinholes of the earlier ones, which 
were not hardened, are more subject to wear. 
Inspect the trigger housing group for looseness, 
and operation. The group should assemble easily 
to the receiver without apparent looseness or side 
play. Forward or rearward movement due to 
clearance at retaining pin should not exceed 
approximately 0.006 inch by hand test. 

c. Trigger Housing Retaining Pin (Fig. 45). 
Old type of trigger housing retaining pin (with 
springs) must be discarded and replaced with new 
type of retaining pin (Fig. 48). (New type pins 
have no spring.) Inspect retaining pin for wear, 
burrs, and rust. 

MOWING. '•K»l»- 4 i**0Oi.lHOwW?| 


■ ■. ■ SA*fTY_7!«W»i 




Mlrtrtm. MMAXM* i llMQtt L<tt*U 
CAM*. AMI - tH'in i Ay; ',■■.:«., 

rCH. MAGA*tN t .,T| W07( , 3H0WW WWtliu ttMUM 

TCH. MA&M!Nfc-H4lt« CATCH AMD saw* 

..',,....■■/. n—*n 

Figure 45. Trigger housing assembly for carbines M1 and Ml AT - exploded view. 



ii$t .' P *05M L 

»» W 'jft»«* 

Figure 46. Trigger spring removal and installation. 

d. Hammer (Fig. 45). 

(1) Depot maintenance. Inspect the ham- 
mer on a comparator where facilities 
are available. This applies to hammers 
removed from used carbines; in general, 
new hammers removed from stores do 
not require comparator inspection. 

(2) Field or depot maintenance. Where 
comparators are not available check 
hammer for worn pinhole, burred or 
dented face or bolt cam, worn or 
burred plunger retaining slot, burrs, 
and rust. Check to see that cocking 
cam is in good condition and that the 
corner of the sear notch is not rounded 
or broken. This comer must be reason- 
ably sharp. Any evidence that the sear 
notch has been stoned is cause for 
rejection. Bearing face of sear notch 
should be level as determined by visual 
check (Fig. 49). Inspect hammer pin 
for wear and burrs, hammer for loose- 
ness on pin, and pin for looseness in 
trigger housing. Movement of hammer 
or pin should be free, but without 
shake. Inspect trigger housing, at point 
of contact with stop lug or left face of 
hammer, for wear and burrs. 

Note. Replace early design hammer 
C57146 with hammer 5653447 of 
recent design (Fig. 49). 

e. Hammer Spring and Plunger (Fig. 45). 
Inspect hammer spring plunger for deformation, 
wear, burrs, and rust. Inspect fit of head of plunger 
in slot in rear face of hammer. Head should seat 
evenly and positively in slot. Inspect hammer 
spring for functioning, deformation, and set. 

Note. Replace early design hammer springs 
that had a free length of 2.125 inches, 22 coils, 
and wire diameter of 0.046 inch with hammer 
spring 5377921 of recent design that has a free 
length of 2.616 inches, 26.5 coils, and wire diam- 
eter of 0.042 inch (Fig. 50). 

f. Trigger (Figs. 45 and 51). 

(1) Inspect the trigger on a comparator 
(depot maintenance) where facilities 
are available. This applies to triggers 
removed from used carbines; in general, 
new triggers removed from stores do 
not require comparator inspection. 

(2) Where comparators are not available, 
inspect trigger for movement on trigger 
pin and pin for seating in trigger 
housing. Trigger should rotate freely 
on pin but have no shake. Pin should 
fit snugly in housing with a push fit. 
Inspect clearance of trigger tip with 
guard, and rear of trigger with housing 
when fully retracted. 

Inspect top of pedestal where sear 

seats when hammer is cocked, for 
levelness, wear, and burrs, and check to 
assure that the top forward corner of 
the pedestal is not rounded or broken. 
This comer should be reasonably sharp. 
Triggers that are rejected for high 
pedestal (as determined by comparator 
LY) will be retained in the shop until 
a sizable quantity has accumulated, 
then disposition instructions should 
be requested from Chief of Ordnance, 
Washington 25, D.C., ATTENTION: 
ORDFM. Check trigger spring notch for 




ftUfiS. WEAR OR 

ch(Ck nous for 



RA PO )30S?fi 

Figure 47. Trigger housing inspection points. 



burrs and foreign matter. Check for- 
ward end of trigger which engages with 
safety for deformation and burrs. 
Check sear spring seating recess for 
foreign matter. 
(4) Test functioning of trigger to determine 
that trigger returns smoothly to its 
forward position with no tendency to 
stick or hang. 
g Trigger Spring (Fig. 45). Check trigger 
spring for deformation and rust. Check seating of 
spring in seating notch in trigger and positive 
retention spring in housing aperture. Bow end of 
spring should seat level in bottom of seating notch 
in trigger, and rear coiled section should be held 
firmly in housing aperture by the force of spring 
tension. Tips of spring should he slightly spread. 
Trigger spring should return trigger to forward 
position under adequate tension (FIELD MAIN- 

ft. Sear (Fig. 45). 

(1) Although sear 7161841 can be used in 
carbines Ml and M1A1, the available 
stock should be conserved for car- 
bines M2 and M3. 

(2) Inspect the sear on a comparator 
facilities are available. This applies to 
sears removed from used carbines; 
in general, new sears removed from 
stores do not require comparator 


T ' ■'■■■ ■ ■■■ : ti 


I — 1 i 1 . ; ■ ;. „ 1 




'■■■" ■■■■ ■•■ ■■■ ■ ■ . ■■ ..■.. ■ . ■ ■■ ■ 

Figure 48. Trigger housing retaining pin. 

V E'"W 





\M\ AMD 

(Ml AND 



Figure 49. Old and new design hammers for 
carbines Ml, M1A1, M2 and M3. 

(3) Where comparators are not available 
inspect sears carefully. The nose should 
have a "fine grind" surface and should 
have a small radius at the point where 
it contacts the sear surface of the 
hammer. The surface at the extreme 
rear end should be flat ground and the 
lower comer or edge should be sharp. 
Some sears 6200978 have been proper- 
ly ground at each end and are usable. 
In this connection reference is made to 
Fig. 52, which is correct as far as it goes 
but is not complete. Sears 5653483 
with the grind quality were manu- 
factured without either of these iden- 
tifying marks and these also should be 
used if otherwise serviceable. The 
important point is to assure that all 
sears used are those on which the nose 
and rear end are properly ground as 
mentioned above. Questionable sears 
should be retained in the shop until a 
sizable quantity is accumulated, where- 
upon disposition instructions should be 
requested of Chief of Ordnance, 
Washington 25, D.C., ATTENTION: 
ORDFM. This does not mean that all 
of the sears that can be determined un- 
serviceable by visual inspection should 
be retained. 

(4) Check sear for movement on trigger 
pin. Sear should rotate freely about 
pin and have backward and forward 
movement due to elongated pinhole 
but should have no vertical play. 
Check pinhole for exesssive wear. 





MS, MAMMO*~AI«6«6J. 7Z 

M8SCNT VANUI : ACTV«~fcE0lJl<<f:i 

36; » '.a 

RA PD 13048V* 

H d . l . ■ . . . .■ ' . ■ ■ h . ■ ' ■ ■ . 

Figure 50. Hammer spring— early and recent design. 

spring is assembled, last coil of spring 
is contracted slightly and fits into 
groove in shank of plunger for re- 
L Plunger Assembly for Magazine Catch and 
Safety (Figs. 45 and 55). 

(1) Check to assure that new type plunger 
assembly is used. Modificiation Work 
Order ORD B28-W-4 replaces the old 
type plunger assembly with the new 
type (Fig. 55). 

(2) Check plungers for wear and the spring 
for functioning, deformation and set. 
Refer to table II for inspection in- 

i. Sear Spring (Fig. 45). Check sear spring 
for positive seating in trigger and sear, and for 
functioning, rust, and set. Visually inspect during 
repair. Replace during rebuild. 

;. Safety (Figs. 45 and 53). Check to assure 
that only the rotary type safety 7162080 is used. 
Modificiation Work Order ORD B28-W-6 prescribes 
the replacement of the old type safety with the 
new type (Fig. 53). Test safety for positive po- 
sitioning. Check for burrs and rust and check 
spring plunger recess and trigger slot for burrs and 
foreign matter. Refer to paragraph / (1) and (2) 
below for inspection of plunger assembly for 
magazine catch and safety. 

k. Magazine Catch (Figs. 45 and 54). 

(1) Check to assure that magazine catch 
7161842 (marked with "M" under- 
lined) or 7160470 (marked "M" 
not underlined) is used. Although they 
are interchangeable, stocks of catch 
7161842 should be conserved for 
carbines M2 and M3. Modification 
Work Order ORD B28-W-4 prescribes 
replacing the old type catch with the 
type (Fig. 54). 

(2) Test the function of the magazine 
catch. Check catch for free movement 
in guideway, deformation, worn or 
burred retainer plunger recess, and 
worn or burred magazine retention 
lugs. See that projection on end of 
catch 7161842 is neither bent nor 
burred. Check magazine catch spring 
plunger for retention on spring, wear, 
and burrs, and check spring for func- 
tioning, deformation, and set. See 
table II, for standards on magazine 
catch spring. When magazine catch 

Note: Use figure 55 only as a guide and 
not as a basis for rejection. Function 
test of plunger assembly during func- 
tion firing is an adequate criterion for 




a. General. Replace all broken, worn, or 
otherwise unserviceable parts. Remove burrs and 
rust. Weapons must have all applicable modi- 
fications, and instructions contained in future 
technical bulletins must be followed. Note that 
certain components for carbines M2 and M3 a e 
not interchangeable with those of the carbine* 
Ml and M1A1, although some designed for the 
former can be used on the latter. 

b. Hammer Fails to Cock. This condition may 
be due to damaged sear, broken sear spring, burrs 
or foreign matter in sear notch in hammer, or 

ciio + ems 

. ■■■: 

" ' ' ' L l L L L l 

■ 9 

■ ■ ' ' L —■ 

0CO TY« 

;-Mfviou$ to 


'■' " L ■ * ! 

ftA«) rjffil4 

Figure 51. Trigger 6200988. 



failure of bolt to move far enough to the rear on 
recoil movement to cock hammer. Examine 
parts; clean and replace if necessary. 
c Correcting Trigger Pull 

(1) A light or heavy trigger pull may be 
caused by foreign matter or burrs in the 
sear notch in the hammer, on the nose 
of the sear, on the top of rear end lip 
of trigger where the rear end of sear 
rests, or in the elongated pivot hofe 
in the sear from seating fully in ham- 
mer notch. To correct, remove foreign 
matter or replace with new components 
from stock. 

(2) A light pull may also be due to a weak 
or broken sear spring which will not 
seat the sear fully in the hammer notch 
before the pressure from hammer 
spring is applied to the nose of sear 
through the hammer. Correct by 
replacing sear spring. 

(3) Uneven surface of hammer notch or 
worn nose of sear may alter trigger 
pull. Correct by replacing sear or 

d. Trigger Hang, Triggers of early manu- 
facture had a 4- or 8-degree angle on the forward 
face of the pedestal which was conducive to trigger 
hang. When trigger hang exists, and it is not due 
to malfunction of the trigger spring, it can be 
eliminated by replacing the trigger with one of 
recent manufacture having an angle of 20 degrees 
on the forward face of the pedestal (Fig. 51). 
Surface must be smooth. 

■ '■ L t « ■ ' ■ 

jv. .'; I 

A ■ ■ ■ 


. ■ ■ ■ . . . . s 

■ .. . . 

■ ■ 



Alio « »#t MM** AN0 ; : -iitailcwfc 

Figure 52, Sears - usable types. 

<MW TVft) SAIWt^lttOW 

' i '.i ■ 


■ S 


!» - ; " 



Figure 53. Safeties. 

e. Trigger Housing Loose on Receiver. 

(1) If T-shaped lug on rear end of trigger 
housing becomes worn so it becomes a 
loose fit in retaining L-shaped Jugs on 
rear end of receiver, peen lightly to 
spread lug, then file to fit. The trigger 
housing must be readily disassembled 
from receiver. 

(2) The forward lugs of trigger housing may 
be similarly treated to attain close fit. 

Caution: Do not peen or squeeze in the 
lugs on the receiver as they are hard- 
ened. Any attempt at tightening 
should be done by peening of trigger 
housing lugs when necessary. 

f. Safety Sticks. If the safety sticks when 
turned the 90 degrees, the safety spring plunger is 
burred or missing or the plunger seats in the 
safety are burred or too deep. Stone the safety for 
proper retention of the plunger or replace with 
new safety. Replace plunger or spring as required. 


a. Refer to page 13 for instructions on the 
assembly of the trigger housing group. 

6. Using trigger spring removing tool 7160026 
(Fig. 46) replace the trigger spring by reversing the 
procedure of removal. When the spring is in po- 
sition in the retaining groove of the trigger, depress 
the trigger and withdraw the tool from the hous- 
ing. Install the stock on the carbine. 


■ H 


i . 

oio 1 

■ ■■ ■■■ 

'W* »• •« ryasafc— 

; : :■;:■ 


. *'. 

U M 1364** 

Figure 54. Magazine catches. 


a Cock hammer and check seating and 
positive retention to limit of sear nose in hammer 
notch. Continue to retract hammer rearward and 
observe forward movement of sear to maintain 
retention. Sear should continue to contact hammer 
throughout movement Pull trigger; sear should 
release hammer crisply. Release trigger. It should 
move positively to forward position under force 
of trigger spring and be held there firmly and 
without shake even when sear is not assembled. 
When trigger is in forward position ahd hammer 
cocked, the sear should rest upon or above top of 
rear pedestal of trigger. 

b. Check trigger pull. See page 50 for in- 
structions on the checking of the trigger pull. 

c. Check to assure that hammer and sear 
reengage when trigger is pulled back far enough 
to cause perceptible movement of hammer and 
then released. 

d. Check to assure that trigger guard is not 
bent and does not interfere with functioning of 

e. Check to assure that safety functions 
properly. It should block the trigger when set on 
safe (tang vertical) and permit release of the 
hammer when the tang of the safety is pointing 

to the rear. 

f. Check functioning of the magazine catch 

to assure that it operates properly and does not 
bind. Inspect each assembly to assure that the 
magazine catch can be pushed rearward in its ways 
in the trigger housing, and that the safety plunger 
spring is strong enough to return it firmly to the 
forward position. Check each safety by rotating 
it to both positions to assure that the retention 
effect of the spring is sufficiently strong to hold it 
firmly in the position desired. It shall be deter- 
mined that the forward pressure on the magazine 

will not prevent proper sidewise travel of the 

g. With trigger housing group assembled to the 
receiver, check to assure against looseness which 
would affect functioning. The retaining pin must 
fit tightly enough to remain in position yet permit 
ready disassembly by hand. The trigger housing 
group must be readily disassembled from the 



a. To remove the trigger housing group the 
disconnector lever must first be removed, as the 
disconnector lever pin locks the housing to the 


b. To remove the disconnector lever, move 

the selector to its rearward position and push the 
selector spring up the slot in the housing magazine 
post to the dismounting notch and withdraw, 
using a drift or the operating slide spring guide. 
Slide the selector off the disconnector lever pin. 
The disconnector lever can then be withdrawn and 
the trigger housing separated from the receiver. 

c. The disassembly of the trigger housing 
group is the same as for the carbines Ml and 


d. To reduce loss of disconnector spring 
plunger assembly when removing trigger housing 
group from barrel and receiver assembly of M2 



' H r . ' ' ' . I .1 ■ ■ ■ 

Jttr tmi 


■ ■ - ■ 




-■- .; 

Figure 55. Plunger assemblies for magazine catch 
and safety. 



and M3 carbines, MWO ORD B28-W7 prescribes 
the following changes: 




7162780 Spring, disconnector Spring 7161836 

7162781 Plunger, disconnector Plunger 7161835 

The above items are components of: 

7162782 Plunger, disconnector Plunger, assem- 
spring, assembly bly 7161834 


a. General. Inspect all parts for damage, 
excessive wear which might cause malfunction, 
burrs, rust, foreign matter in recesses, deformation 
and free action with mating parte. Reference is 
made below to pages in the preceding section 
for inspection of corresponding components of the 
trigger housing group. 

b. Trigger Housing (Fig. 56). See page 62 for 
inspection of the trigger housing. Also inspect the 
selector spring retention slot in left magazine post 
for foreign matter and positive spring seating so 
that spring will not turn when assembled. 

c. Hammer (Pig. 56). See page 63 for in- 
spection of the hammer. Also inspect milled cut 
on lower right sight of hammer, which allows 
clearance for disconnector, for burrs and wear 
(Fig. 49). 

e. Trigger (Fig. 56). See page 64 for in- 
spection of the trigger. 

/. Trigger Spring (Fig. 56). See page 64 for 
inspection of the trigger spring. 

g. Sear (Fig. 56). See page 64 for inspection 
of the sear. Also inspect top front portion (cam- 
ming surface for disconnector) for burrs and wear. 

h. Sear Spring (Fig. 56). Check sear spring for 
positive seating in trigger and gear. Check for 
functioning, rust and set. Visually inspect during 
repair. Replace during rebuild. 

L Safety (Fig. 56). See page 65 for inspection 

of the safety. 

/. Magazine Catch (Fig. 56). See page 56 for 
inspection of the magazine catch. 

k. Disconnector (Fig. 56). See that bearing 
slot in front end of disconnector is free from 
foreign matter and burrs and is lightly lubricated. 
See that disconnector spring is not weak, rusted, 
or broken, that spring well is free of foreign 

-■j ..yuW . 
j : -HhWSM-.:.»iWi3 
I, :WW0H.-.JI*MS? 

"-"MOW- ■&***« ■'■■ '■ 

tAlCM A»» .>■<■%•.> 

*- t*»SK W*0*W« ■ TI0IHI 

Kg- ru 

H - 
ft* I'D 1W477A 

Figure 56. Trigger housing group - carbines M2 

and MS. 

matter, and that plunger is free of burrs. Lubricate 
plunger occasionally. Expanded end of coil of 
spring should seat in plunger for retention. Check 
rear end of disconnector for burrs and wear. 

/. Disconnector Lever Assembly (Fig. 56). 
Examine the rivet of the disconnector lever as- 
sembly which pivots the lever in the flat crank 
shaped end of the pin, to determine that the rivet 
is secure, that the hole in the crank of the pin is 
not enlarged, that this pivot is free from burrs, 
and is not worn. See that lever is not distorted or 
twisted on rivet, that it is free to rotate on the 
rivet and that ends are free from burrs and wear. 
Offset in rear section of lever is for alignment 
with disconnector and should not be straightened. 
Be sure toe (front end) of lever hears squarely on 
cam on operating slide and is (slide retracted) 
under raised boss when lever is fully seated in the 
housing. See that holes in trigger housing for pin 
of disconnector lever assembly are not enlarged. 



Rear end should not bind in cam of disconnector 
when assembled. Examine pin of disconnector 
lever assembly to see that pivot areas are free from 
burrs and not worn. Keep pivots lightly lubricated. 
If the pin is rotated by the selector so as to permit 
inadequate positioning of lever in full automatic 
fire, inspect the straddle cuts in pin which engage 
the' selector. They must be free from burrs, must 
retain selector firmly, and must not be wom so 

as to cause lost motion. 

m. Selector and Spring (Fig. 56). See that 
disconnector pin slot in selector is not wom so it 
will cause lost motion or impair security. See that 
spring recess in rear end is free from foreign 
matter and will retain spring securely. See that 
selector spring is bent in only one plane (not 
twisted) and both ends seat securely in their 
retention recesses. If spring is loose when as- 
sembled, straighten slightly. 


The repair and rebuild of the trigger housing 
group is essentially the same as for carbines Ml 
and M1A1. See page 65. 


a The assembly of the trigger, trigger spring, 
sear and sear spring is the same as for the carbines 
Ml and M1A1 (page 66). Use sear 7161841 (page 
64) and magazine catch 7161842 (page 65) marked 
with underlined letter "M" on all carbines M2 
and M3. To assemble the disconnector and ham- 
mer, place the disconnector in trigger housing 
so that the lug projects over the right side of the 
housing. Insert the hammer on the left of the 
disconnector so that its milled lower cut presses 
against the flat portion of the disconnector. 
Insert the hammer pin from the left side and 
through the hole in the hammer, line up the hole 
in the disconnector and push the pin through the 
hole in the other side of the housing. With the 
pin head on the left side, the pin is prevented from 
shifting when the carbine is assembled. 

b. Insert disconnector spring plunger as- 
sembly into the hole in the top of the discon- 
nector, spring first. Use disconnector spring plun 
ger assembly 7162782 on all carbines M2 and M3. 
Line up the trigger housing with the receiver and 
insert the disconnector lever pin from the right 
side with the long leg of the lever towards the 
front. The rear toe of the lever should rest on the 
bottom surface of the projecting lug of the dis- 

connector. Slide the slot of the selector through 
-the grooves of the projecting portion of the dis- 
connector lever pin. Pivot the selector to the rear 
position and insert straight end of the selector 
spring into the recess in the lower rear end of the 
selector; with the loop of the spring downward 
insert the loop end into the slot in housing maga- 
zine left post mounting slot and down to the 
bottom of the post. 


a. For functional check of the trigger housing, 
hammer, trigger, sear, magazine catch, and trigger 

pull, see page 67. 

b. Set for semiautomatic fire. Squeeze the 

trigger, cock the hammer, and forcibly strike the 
grip of the stock with the heel of the hand several 
times. If the hammer falls, the group is not ac- 
ceptable because it will tend to fire in an uncon- 
trolled manner. 

c. With the trigger housing assembled to the 
receiver, check functioning of all moving parts 
at full and semiautomatic settings. 

d. Check to assure that there is no binding 
between hammer, disconnector, and housing. 

e When the carbine M2 is set for automatic 
fire with the trigger pulled back, the hammer must 
fall when the operating slide is slowly pushed all 
the way forward. When set for semiautomatic fire, 
the toe of the disconnector lever should clear the 
cam on the operating slide to assure that the ham- 
mer will not be released. 

f. Check trigger pull {page 50). 



a. Refer to page 7 for instructions on re- 
moval from carbine and disassembly of the oper- 
ating slide assembly. 

b. Before the operating slide on the carbines 
M2 and M3 can be removed, the disconnector 
lever must be removed first. 


a. Operating Slide (Fig. 57). Check slide for 
bent or cracked rear bar, deformation, excessively 
worn guide lugs, burrs, and corrosion. Inspect 
bolt camming lug recess for wear and burrs. Inspect 
spring guide seating recess in rear face for wear, 
burrs, and foreign matter. Inspect front race of 



slide where it contacts piston for levelness. Un- 
evenesB at thiB point may cause malfunction. 
Check camming surfaces for burrs and wear (Fig. 
58). Inspect the operating slide under "black light" 
for cracks in the areas specified below (DEPOT 
MAINTENANCE ONLY). Reject slides having 
cracks around the operating cam, at the junction 
of the inertia block and arm, and around the 
disconnector lever cam on M2 type slide 7161843. 
Check visually and reject operating slides showing 
breaks around the hole for the operating slide 
stop. Cracks at this point are acceptable. Use 
operating slide 5357151 (usable) or operating 
slide 7160091 (preferred) on carbines Ml and 
M1A1 until the supply is exhausted, then use 
7161843 (Fig. 58). Until the supply of the two 
former slides is exhausted, conserve operating 
slides 7161843 for use on carbines M2 and MS. 

b. Operating Slide Stop and Stop Spring 

(Fig. 57). 

(1) For depot maintenance, check to assure 

that stop 7312452 and spring 7312453 

are used. For field maintenance, old 

type is satisfactory if it functions 


(2) Inspect stop for wear and burrs, loose- 
ness in operating slide, and rust. Inspect 
stop spring for functioning, lack of 
friction with stop, and for set. Inspect 
spring for foreign matter. 

c. Operating Slide Spring (Fig. 74). Inspect 
operatng slide spring for set, broken coils, and 
distortion. Refer to TB ORD 366 for operating 
slide spring standards. 

d. Operating Slide-spring Guide (Fig. 74). 
Inspect operating slide spring guide for defor- 
mation, burrs worn or burred nose, and rust. 
Shank of guide should be straight. Nose of guide 
should be free from burrs to insure positive seating 
in its recess in rear face of operating slide. With 
spring assembled to guide, insert in housing, or 
in housing tube in early type receivers, and hand 
operate to test freedom of movement. 

e. Slide Spring Housing (early type receivers). 
Inspect inside and outside of operating slide spring 
housing for dents, splits, rust, and foreign matter. 
Inspect spring retainer for looseness in tube and 
positioning lug on retainer for burrs and wear. 
Some tubes have a pressed out lug on the side and 
a slot in the rear. This lug seats in the operating 

«N, STOl» • ^WW. -. 1 '- ! 1 "' ' " 1 '^ ' "- ' 
SPRING, S*»W ,«0f ,-.; A 

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Mt'ANfr MU.t $WY 

Figure 57. Operating slide assembly. 



slide dismounting slot in the receiver (limited 
design), and the rear slot mates with a small 
projecting lug in the rear end of the housing tube 
bed groove in the receiver. The lug should not be 
bent or burred, and the edges of slot should be 
clean. If lug is damaged or missing, replace the 
tube with a new one. 

Note. Do not use these early type receivers 
in rebuild. 



a. In the early type receiver which contains 
the operating slide spring tube, if the retainer in 
the rear end of the tube becomes loose, tighten 
it by crimping tube in with cold chisel. If too loose 
to be easily tightened, replace the housing as- 
sembly. Repair and rebuild of the operating slide 
assembly consists of replacing worn, damaged 
parts and elimination of burrs, etc. 

6. It is advisable to drill a 3/16-inch hole 
through the rear end of the receiver into the 
operating slide spring hole for the purpose of 
having good circulation of phosphating solution 
and preservative compounds. 


Refer to page 13 for instructions on the 
assembly of the operating slide assembly. 


A. Check slide to assure that the operating 
slide stop, spring, and pin (slide 5557151) have 
been assembled. Check the functioning of the stop 
by hand to asssure that the spring exerts sufficient 
pressure on the stop to retain it firmly. 

b. With operating slide assembled to barrel, 
receiver, and bolt, and without slide spring and 
guide assembled, manually operate slide and check 
for smoothness of operation of bolt and slide. 
Inspect bolt camming recess for retention with 
bolt cam lug, and operating slide rear guide lug for 
retention with guideway in receiver. It should not 
be possible to disengage slide from guideway in 
receiver. A slight pull out and up at rear end of 
guideway should disengage slide from receiver, but 
not from bolt cam lug. This should not be possible, 
without undue force, until barrel guide lugs on 
slide are aligned with relief cut in left barrel 
guideway and slide is rotated. If slide can be 



. Ml MO WAV 

— - — — - — r- 

. i 

00 wot Utt 


60 NOt VU 


-r-TpT-ir ■ ■■' ■ 

Figure 58. Slide, bolt, extractor and plunger. 

disengaged otherwise, rear bar is bent or guide 
lugs are excessively worn. 

c. With operating spring and guide installed, 
test function of operating slide stop. When bolt is 
fully retracted and stop pressed into its retaining 
groove, it should positively "hang" slide and bolt 
in that position. If slide does not remain in rear- 
ward position, the stop and/or retaining groove 
are worn or stop friction spring is missing, broken, 
or set. Stop should be cammed out of groove and 
lie flush with bottom surface of slide when bolt is 
retracted. Friction pressure of stop spring should 
be sufficient to hold stop positively in retracted 
position notwithstanding jar of bolt at end of 
rearward movement. (Stops of early design were 
spring retracted when slide was moved slightly to 
rear to relieve friction between stop and face of 
notch in receiver. ) 



d. Check to assure that the operating slide 
can be drawn all the way back to its atop against 
the receiver without binding. 




o. Refer to page 13 for instructions on re- 
moval from carbine of the bolt assembly. 

b. Assemble bolt disassembling tool 7313298 
(Fig. 6) to the bolt (Fig. 60), with the unslotted 
tang of the tool pawl resting under the bevel of 
the extractor plunger. (Bolt disassembling tool 
7313298 is supplied to organizational personnel 
and to ordnance field and depot maintenance 
personnel.) White pressing down on the unslotted 
tang of the tool pawl to make certain that it stays 
under the bevel of the extractor plunger, turn the 
thumb screw until the extractor plunger is de- 
pressed making it possible to remove the extractor 
by forcing it out through the hole in the tool. 

Caution; If the tang of the tool pawl is not 
kept under the bevel of the extractor plunger, it 
will come in contact with the straight portion of 
the plunger shaft and continued pressure of the 
thumb screw will cause the tang of the tool pawl to 


c. Remove tool slowly keeping finger over 
tang and plunger to keep plunger from popping 
out and disassemble bolt. 

Note. Any effort to "punch out" the ex- 
tractor without depressing the extractor plunger 
will shear off the plunger or the extractor retaining 
Up. The plunger must be depressed before the 
plunger is "punched out. <»«» 

Figure 59. Bolt assembly. 


e. Replace and dispose of all used extractor 
plunger springs during rebuild. 

f. Extractors, with "V" type retaining notch 
or modified retaining notch, will be replaced and 
disposed of during rebuild. Use only new type 
plungers as shown in figure 58 and only previously 
unused plungers and plunger springs. 

g. Visually inspect the ejector assembly for 
wom, deformed, or broken spring and for con- 
dition of ejector. Function test ejector. 

ft. Check to assure that only the new type of 
modified type firing pin (Fig. 61) is used. The old 
type pins can be modified by depot maintenance 
if the quantity involved warrants the work re- 
quired to accomplish this (Fig. 62). Function test 
bolt and firing pin. 


a. Inspect bolt for cracks (under "black light" 
in depot maintenance), paying particular attention 
to the area around the right hand locking lug. 
Bolts having cracks must be rejected. 

b. Check to assure that bolt is free from burrs 
and excessive wear especially around the hammer 
cam at the rear. Bolts with badly galled or notice- 
ably worn cams must be rejected. Inspect firing pin 
tang slot for wear and burrs. 

c Inspect the firing pinhole at face of bolt. 
The comer should be free from burrs, but not 
rounded or chamfered. 

d. Visually inspect to assure that there are no 
burred edges at the two cams on the operating lug. 


\ £xtr*cto ~*aoow : 

\ K)IT:-71WOT2 




/ ww of root 



Figure 60. Disassembling bolt. 






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, ■■ "V< .-'V 

■ ■ ■ ■ 


4 ' ^^^v^~ l V iff* 

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■ ' ■ 

Figure 61. Bolt and firing pin. 

i Check to assure that only full round bolts 

7160092 are used in the carbines M2 and MS 

(Fig. 58). Bolt 557148 will be used in carbines 

Ml and M1A1 in so far as practicable in order to 

conserve supply of bolt 7160092 for use in the 

carbines M2 and M3. 

j. Visually inspect to assure sufficient firing 

pin protrusion and proper contour of firing pin 
point. (The firing pin protrusion should not be 
less than 0.048 inch DEPOT MAINTENANCE 

k. Check assembled bolt to insure that ex- 
tractor shank does not protrude beyond body of 


L Repair and rebuild of the bolt group con- 
sists of replacing worn or damaged parts. Bolt 
faces and other parts subjected to burned powder 
residues must be thoroughly cleaned. Scrub these 
parts with a bristle brush moistened with rifle- 
bore cleaner. 


a. Insert ejector and ejector spring so that 
recess in ejector, when it is depressed, will line up 
with inside surface of the bolt to permit complete 
entry of the extractor. 

b. Insert extractor spring and plunger. Po- 
sition the plunger so that its flat surface will match 
the inner flat surface of the extractor retaining 


c. Place bolt disassembling tool 7313298 on 

bolt (Fig. 60) so that slotted tang of its pawl 
rests on extractor plunger. (The bolt disassembling 
tool 7313298 is supplied to organization personnel 
and ordnance field and depot maintenance person- 
nel.) Turn thumbscrew of tool until plunger is 
depressed; at the same time, the ejector is de- 
pressed into bolt by the tool. 

A Insert firing pin and extractor and remove 



a. Test bolt for freedom of movement in its 
guideways in receiver. Check freedom of move- 
ment of firing pin in bolt, fit of tang in slot, and 
protrusion of nose of pin from face of bolt when in 
forward position. Firing pin should move freely in 


b. Check functioning of extractor and ejector. 
Ejector should return forcibly from depressed 
position. When ejector is depressed, it should not 
extend beyond front lip of bolt because it is likely 
to cause interference with feeding. 



a. Do not remove front sight unless necessary, 
as the body of the front sight is crimped over both 
ends of the front sight pin, and front sight key is 
staked at the rear end in its keyway in the barrel. 
When original finish is reasonably satisfactory, the 
removal of front and rear sights and front band to 
permit sand blasting, in order to obtain the highest 
quality protective finish, is not required. 

b. Remove the front sight as follows: 

(1) With the barrel and receiver in a padded 
vise, the muzzle protruding about 
1 inch beyond the jaws of the vise, and 
the front sight vertical, drive out front 
sight pin from left to right, using a 
3/32-inch drift. 
Position front sight removing tool 
7161237 over front sight, hooking it on 
the rear of the sight (Fig. 63). 


,0 0(10 : 




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Figure 62. Firing pin 6200976. 

RAPD 13052* 



(3) Enter pilot of tool screw into end of 
barrel and remove front sight by 
turning handle of tool. 


q. Check sight to see that it is tight on the 
barrel and free from malformation and burrs, and 
to assure that the barrel has been staked at the 
rear end of the front sight key way* In any staking 
at this point, caution must be exercised to avoid 
distortion of the base. It is required that the front 
sight be tapped forward on the barrel to take up 
any clearance between the key, keyway, pin, and 
sight and that the metal of the barrel at the end of 
the keyway be upset against the key to secure the 
sight in this position. 

b. Check to assure that staking of the front 
sight keyway and the application of the proof- 
mark have not distorted the bore. 

c. Check to assure that the ring portion of 
the front band surrounds the barrel with spring 


d. Check crimping of front sight; it must be 
crimped at each end of the pinhole to prevent the 
pin from coming out 

a Inspect wings; any deformation due to 
installation of sight on barrel or otherwise is cause 
for rejection. 

f. Check height of blade; it must be not less 
than 0.140 inch, measured from the base of the 
blade. This is necessary for a good sight picture* 
In actual practice, it has been found necessary to 
maintain a height of approximately 0,315 inch in. 
order to target by bore sighting. Sights, not con- 
forming to this 0.315-inch dimension, will be 
retained for reworking. 

tk$HX SiOHfW 

<A v> T304WA 

Figure 64. Aligning front sight 

g. The height of the blade is adjusted by 
depot maintenance so that the carbine will meet 
the targeting requirements defined on page 102. 
This is done by filing down the blade. The blade 
contains sufficient stock to adjust height during 

h. Inspect the top of blade; it must be square 
and coated with Magic Blue (or similar substance) 
to prevent gloss and preserve the surface. 


Looseness of the front sight on the barrel is 
usually caused by a loose key which is inade- 
quately staked. The key can be tightened by 
tapping it forward against the front end of the 
keyway and then staking the rear end of the key- 
way firmly against the rear end of the key. Care 
must be taken not to distort the base. If the key 
has side movement* replace the key or, field 
maintenance may peen the key lightly if a new key 
is not available. 

** ro \ »o**oa 

Figure 63. Removing front sight. 


Caution: The front band must be assembled 
on the barrel before the front sight is assembled. 

Place front sight key in keyway in top of 
barrel at muzzle with pin notah facing up. Tap 
key snugly toward front end of keyway and stake 
metal of sight over both ends of pin to hold it in 
position. Slide front sight on barrel with sloping 
faces of wings to rear. Using front sight assembling 
tool 716313 mate keyway and key in barrel 
(Fig, 64) and drive sight on barrel (Fig. 65) until 
pinhole in sights is in alignment with pin notch 
in key. Install front sight pin and stake metal of 
sight over both ends of pin to hold it in position. 




■A M> 'MHMA. 


Figure 65. Installing front sight. 

Drive sight forward and stake barrel against rear 
end of key. 

Note. If practicable, the front sight will he 
kept mated with the barrel and receiver assembly 
from which it was removed. 



Carbines of early manufacture were equipped 
with an "L" type (leaf type) rear sight (Fig. 66) 
composed of two integral leaves set at right angles 
to each other. By Modification Work Order ORD 
B28-W3 this sight is replaced by the adjustable rear 
sight. All. carbines of later manufacture are e- 
quipped with adjustable rear sight 6573955 or 
7160060 (Fig. 67), which differ only in method of 
manufacture. Sight 6573955 is a machined type, 
and sight 7160060 is a stamped type. The function 
and operation of both sights are identical. 


a. Scribe a mark on the receiver directly 
opposite line on sight base for sight assembly 
6573955 (machined type) and in the receiver 
directly opposite mark on zero sight plate for 
sight assembly 7160060 (stamped type). This is 
necessary for proper alignment in assembly. 

b. Place adjustable rear sight assembling 
tool 7312068 on the receiver with the lip of the 
tool riding on the operating slide guideway in the 
receiver. If the sight is of the stamped type, insert 
spacer (Fig. 69) (hanging at end of chain on tool) 
in place to prevent distortion of sight base wings. 
With the right hand jack screw retracted to the 

extreme position and out of the way, slide the tool 
over the sight (Fig. 68). 

c. Push guide of tool (sliding member to 
which chain is attached), so that inside end rests on 
side wing of sight base, fit recess of connector over 
outside end of guide and tighten left hand jack 
screw. As pressure is applied, tap connector with a 
brass hammer and take up slack with jack screw 
until sight is removed. 


o. Check sight base for looseness and sides of 
base will not be bent or distorted; damage of this 
nature may be caused by assembling and disas- 
sembling. Check ramp for worn or burred guide- 
ways and index ball retention notches on the floor 
of the sight ramp . 

b. Check windage screw for wear of threads, 
burrs, security and staking, and check windage 
screw knob for wom knurling. The windage knob 
must be free enough for hand operation, move 
with distinct clicks, and retain its setting. It should 
be possible to move the ramp to extreme limit on 
either side without objectionable binding. With 
ramp centered in sight base, press windage knob 
to left and release to test spring action of index 
ball on knob. There should be merely lateral 
movement of the knob due to pressure and index 
spring action. When released, there should be 
clearance between inner face of knob and sight 

c. With ramp centered in sight base, attempt 
to move lower end of ramp from side to side. 

itAf rr«~-«jia*©3 


rv« M*« WCHTS 

PA TO *97*IB 

Figure 66. L-type (leaf type) rear sight assembly, 



There should be practically no lateral movement. 
If movement is present, it indicates worn threads 
on either windage screw, ramp, or both. Press 
rear end of ramp down and release to check spring 
action of ramp guide plunger. 

d, Move aperture slide up and down full 
length of ramp. Slide should move freely but with 
distinct clicks and be positively retained at each 
sight setting. The slide should be stopped at the 
front (lower) end of the ramp and at the rear 
(top). There should be no undue looseness of the 
aperture slide in the ramp guideways. Inspect peep 
hole for absence of shine and foreign matter. 

' e. On the stamped type sight, the index plate 
should be so positioned that the index line is 
in the approximate center of the base. (In other 
words, the index plate must not be rotated to one 


SC»*«WUGI - 51MW 


'- '" ■''■ ''' 

Figure 67. Adjustable rear sight assembly for 

M1.M1A1 and M2 carbines. 


Figure 68. Removing adjustable rear sight. 

side or the other on its pivot because the full 
range of adjustment of the plate is intended for 
the user of the weapon.) The rivet should be tight 
enough to retain the plate firmly in its set position. 
/ On the machined type sight, the index 
plate should be positioned approximately in the 
center of the ramp and the screw must be tight 
enough to retain the plate firmly in that position. 

g. After targeting (DEPOT MAINTENANCE 
ONLY) and adjustment of the rear sight on the 
receiver, check to assure that the overhang of the 
rear sight base does not exceed the following 

limits: m 

(1) The right-hand side of the sight base 
should not be pushed to the left be- 
yond the point where it is flush with 
the side of the dovetail on the re- 

(2) The sight should be pushed onto the 
receiver far enough so that the left- 
hand side of the base is flush or beyond 
the left-hand side of the dovetail on 
the receiver. 

h. After targeting, check to assure that the 
receiver is staked to retain the rear sight firmly 
in place. 


o. Repair. As the adjustable rear sight is 
replaceable only as an assembly, no replacement 
spare parts are furnished for field repair. Check 
machined type sight for loose or missing index 
plate and screw. The sight should be kept clean and 
lightly oiled to prevent rusting and insure proper 



6. Refinishing. To remove corrosion from the 
rear sight assembly without removing it from the 
barrel and receiver assembly, proceed as follows: 

(1) Sand blast the adjustable rear sight 
assembly, when necessary, using fine 
grit and a controlled air pressure. 

(2) Blow accumulated grit and dust from 
the assembly with compressed air 
having a moisture filter. 

(3) Phosphate finish the assembly. 

(4) After finishing, thoroughly rinse, dry, 
and oil the assembly with water dis- 
placing oil. 

(5) Test rear sight ramp to determine that 
it traverses completely to left and right 
without binding. 

(6) Test aperture and it must move freely 
up and down the ramp under normal 
finger pressure. 

c. Cleaning. The sight is cleaned best with a 
small brush and clean cloths. Remove light rust 
with preservative lubricating oil. Use crocus cloth 
for removal of heavy rust, but since its use pro- 
duces shine, exercise caution. When cleaning, move 
ramp and aperture slide in order to clean thor- 
oughly under them. 

d. Oiling. Immediately after cleaning, apply 
a light film of preservative lubricating oil to all 
exposed metal surfaces to prevent rusting. Excess 
oil will collect foreign matter, which will clog the 
sight and cause excessive wear. A small drop of oil 
on index balls and ramp guide plunger will lubri- 
cate and preserve these parts and their compo- 
nent springs. Such oiling is best done with the 
dropper of the oiler, or a broom straw dipped in 
oil. Wipe off excess oil. 

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lOOt. ASKM81IM5, «**:' 

Figure 69. Rear sight assembling tool with spacer. 

Figure 70. Moving rear sight in place with torque 

Note. When cleaning the carbine, apply a 
small drop of oil to the aperture slide guideways 
in the ramp, the threads of the windage screw, 
the index balls, and ramp guide plunger. Use 
preservative lubricating oil (medium) above +32 
degrees F. and in humid climates, and preservative 
lubricating oil (speical) below +32 degrees F. 

e. Loose Sight Base. If the sight base becomes 
loose in the receiver, tighten it by restaking the 
receiver into either of the two notches in the 
dovetail base of the sight. If base has shifted, it 
should be realigned and restated. If sight has been 
staked properly, it can be restaked in the same 
place. If necessary to restake at other than the 
previous points of staking, file new idents in sight 
base and stake receiver opposite the new indents. 
Make certain that points of staking are one-six- 
teenth of an inch from edges of dovetail slot and 
directly opposite the indents. If staking fixture 
does not line up with idents in sight base, perform 
staking free-handed as outlined above. 


a. Press new rear sight into right side of dove- 
tail by hand. 

b. Center the aperture ramp on the sight base. 

c. If stamped type sight is being placed on 
receiver, place spacer attached to assembling tool 



Figure 71. Peening 
dovetail slot. 

receiver to reduce oversize 

7312068 in place for reinforcing the side wings 

of sight (Fig. 69). 

d. Place assembling tool on receiver with lip 

of assembling tool engaging operating slide guide- 
way in receiver. 

e. Move assembling tool to rear until dovetail 
guide (sliding member) on tool will enter dovetail 
slot in receiver. 

f. Tighten right jack screw by hand until 
block of jack screw is against the side of sight. 

g Insert torque wrench 41-W-3628-85, and 
move the sight into the dovetail slot (Fig. 70). 
Wrench should show an applied torque reading of 
between 18 and 54 inch-pounds. If the reading is 
not within the above limits, remove sight and 
proceed as follows: 

(1) If reading is below 18 inch-pounds 
indent the area in front of the dovetail 
slot. This can first be done by using 
punch 7312234 (Fig. 73) and rapping 
punch with a hammer. Undertake this 
operation with extreme caution. A 
blow only hard enough to cause a flow 
of metal into the dovetail slot is nec- 

(2) If reading is above 54 inch-pounds, 
file the bottom of the sight base as 
shown in figure 72. Do not attempt to 
file the edges of the sight base and 
under no circumstances should the 
receiver be filed. 

Caution: Reading on torque wrench should be 
taken during movement of the wrench, as reading 
taken when starting the wrench will be high, due to 
starting torque in moving jack screw. Exercise 
great care during the procedure outlined in g 
above, as the dovetail base of the sight is hardened 
as well as the dovetail slot in the receiver. Be- 
cause of this, it is necessary that the load limits as 
prescribed and as indicated on the torque wrench, 
be rigidly maintained. If too great a pressure is 
exerted in the placement of the sight, the receiver 
of the carbine will crack or break; and if too light 
a pressure is exerted, the sight will work loose 
under the shock of firing. 

h. Continue operation above until zero line 
on sight base (machined type sight) or zero sight 
plate (stamped type sight) is aligned with scribe 
mark on rear of receiver. 

i Remove the tool from the receiver. 

I Screw ramp of sight to extreme left. 

h. Stake rear sight in place. 

Note. The staking operation is extremely 
critical and success of this operation will depend 
largely upon the skill and judgment of the oper- 
ation (Fig. 73). Bear in mind that the sharp upper 
edges of the dovetail slot on the receiver are 
easily chipped or cracked, and such damage will 
ultimately result in an unserviceable weapon. 
Many problems will arise which will have to be 
solved by the individual mechanic; a few of these 
problems and their remedies are listed in (1) 
and (2) below. 

(1) Indents on sight base dovetail may be 
horizontally misaligned with references 
to holes in sight base. If the indents are 
slightly out of horizontal alignment 
they may be corrected by enlarging 
the indents very slightly with a small 
three-square file. 



Figure 72. Filing roar sight base to fit undersize 
dovetail slot. 



(2) Sometimes sufficient material is not 
available on the receiver to permit an 
adequate staking job. This is partic- 
ularly true when the sight is moved to 
one of its extreme positions. In this 
case, the procedure outlined in (1) 
above should be followed and new 

indents made to permit adequate 

/. On the machined type adjustable rear 
sight the index plate is held in place by a small 
screw. On some of these sights the screw is staked 
in such a manner as to prevent its removal. Take 
care, when zeroing the rifle by a movement of the 
index plate, to loosen the screw only enough to 
permit movement of the index plate. 

m. The index plate on the stamped type sight 
is directly below the ramp and in the center rear 
portion of the sight base. Move this plate with a 
small drift to prevent damage to any of the com- 
ponents of the sight and weapon. 



a. Removing Barrel From Receiver (DEPOT 
MAINTENANCE ONLY). Do not remove the 
barrel from the receiver except for replacement of 
a new barrel. Replace barrel if it is bent or dam- 
aged, if the chamber is worn to the extent of 
effecting excessive headspace or if it does not meet 
the requirements specified in table III. Completely 
disassemble all components from barrel and 
receiver. Place barrel in jaw protected vise. Allow 
enough of the rear end of the barrel to project 
from the vise to permit the wrench 711.3308 to 
be positioned over front of receiver (Fig. 76). 
Place wrench over receiver near barrel and unscrew 
coun tcrcloc k wise . 

b. Removing Gas Piston and Piston Nut 

(1) The gas piston and piston nut are the 
only removable parts of the gas cyl- 
inder group. To. remove the piston, 
clamp the barrel firmly in a vise with 
protected jaws, and using gas piston 
nut removing tool M5 5621065 or gas 
cylinder reconditioning tool 7160995 
(with wrench component), unscrew the 
piston nut counterclockwise from gas 
cylinder (Fig. 77). Take care not to 
bur or twist prongs on nut when 


removing (nut is staked in place) or 
piston will not move freely. Remove 
nut, elevate muzzle of barrel, and slide 
piston out of gas cylinder. If necessary, 
tap cylinder lightly with a wooden 
block to slide piston out. If nut does 
not loosen readily, soak with pre- 
servative lubricating oil, special, for 
about an hour to loosen. Oil can he 
dropped through gas port drill hole in 
gas cylinder. 

If piston becomes "frozen" in the gas 
cylinder due to carbon or rust, soak 
with preservative lubricating oil (spe- 
cial) for about an hour and then work 
out of cylinder. When the nut and 
piston are removed, clean gas cylinder 
and piston thoroughly and oil lightly. 

ror viiw 

Figure 73. Rear sight showing staking. 



(3) The gas cylinder may be integral with 
the barrel, or swaged on the barrel at 
manufacture. Do not remove the gas 
cylinder. If gas cylinder is unservice- 
able, barrel assembly should be re- 


a. Receiver (Figs. 74 and 75). 

(1) Inspect operating slide spring well for 
rust or foreign matter. Visually inspect 
receiver for break-through of the 
operating shde spring hole. This break- 
through occurred in the original manu- 
facture of some receivers because of 
the drill running out through either 
the bottom or right-hand exterior 
surfaces. If the forward end of the 
break-through is 3 inches or more from 
the front end of the receiver, it is 
acceptable; otherwise, it must be 
LY). Any sharp or feather edges around 
this break-through are to be removed. 

(2) Inspect receiver under "black light" 
(Magnaglo or approved equal) for 
cracks in the area around the bolt 
locking slot at the right hand side 
and at the front and rear trigger hous- 
ing retaining lugs (DEPOT MAIN- 
TENANCE ONLY). Receivers having 
cracks extending in both directions 
around a comer must be rejected. 

(3) Visually inspect condition of firing pin 
retracting cam mating cut in the bridge 
of receiver (Fig. 78). This cam was cut 
to an angle of 33 degrees in the earlier 
manufacture of receivers and later to 
45 degrees. Both are acceptable if in 
good condition. 

(4) Visually inspect trigger housing re- 
taining pinhole in the receiver. If out 
of-roundness is apparent, reject the 

(5) Inspect the bullet ramp in the receiver 
to assure it is clean and smooth for 
proper feeding of the ammunition. 
Burrs and sharp edges should be re- 
moved by careful polishing with fine 
emery cloth. The lower edge of the 

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Figure 74. Barrel and receiver group Ml, M1A1, M2 carbines. 



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Figure 75. Barrel and receiver group M3 carbine. 

bullet ramp (where the angular surface 
intersects the vertical) should be 
smoothly rounded. 

(6) Inspect receiver for looseness with 
barrel, deformation, rust and burrs. 
If receiver is disassembled from barrel, 
inspect for worn or crossed threads in 
barrel aperture (DEPOT MAINTE- 

(7) Inspect bolt guideway and locking 
shoulders for wear, burrs, cracks, and 
foreign matter. Inspect receiver re- 
taining lug on rear end (Pigs. 78 and 
104) for wear, burrs, and looseness 
with recoil plate when assembled to 


(8) Inspect operating slide guideway on 
right side for wear, burrs, and foreign 
matter, and operating slide removal cut 
for wear and burrs. Inspect operating 
slide stop detent aperture for wear, 
burrs, and foreign matter. Forward 
surface of aperture should be at a sharp 
right angle to receiver, and with a clean 
edge to facilitate retention of stop, and 
rear face smooth and sloping to facil- 
itate camming. Inspect the rear inside 
face of receiver for foreign matter. 

t>. Barrel. 

(1) General inspection. Inspect barrel for 
deformation, alignment with receiver, 
and for rust, corrosion, and burrs. 
Inspect gas port for foreign matter and 
inspect extractor cut in rear face for 
burrs and foreign matter. Inspect 
operating slide guideways for excessive 
wear, burrs, and foreign matter Burred 
or damaged muzzle end causes in- 

(2) Inspection for serviceability. 

(a) Inspection of barrel for service- 
ability is based principally upon 
accuracy, and inspectors are guided 
by this requirement. Accuracy is 
reduced in varying degrees by the 
following defects; bulges, erosion, 
and pits (table II). Before a barrel 
is inspected for serviceability, foul- 
ing and oil should be removed 
and the bore wiped dry. 

(b) Place barrel reflector in the cham- 
ber and examine the bore from the 
muzzle and breech. If no barrel 
reflector is available, place a piece 
of white paper or rag in receiver 



WMPW> Mfiim handu 

Figure 76- Removing barrel from receiver, 

and hold barrel so that light is 
reflected into chamber and bore, 
(e) If the bore contains small pits but 
has sharp and uniformly distinct 
lands, is free from bulges, and is 
not otherwise deformed, it is 

(d) If the barrel contains a bulge, it is 
unserviceable. This condition is 
indicated by a dark ring in the bore 
and may often be noticed through 
a bulge or raised ring on the barrel 

(e) If the barrel is pitted to such an 
extent that the sharpness of the 
lands is affected, or if it has a pit 
(or pit«) which extends the width 
of a land or groove and is three- 
eights inch long or longer, the 
barrel must be rejected. 

(/) During the inspection of the bore 
from the breech, give special 
attention to the chamber. Pits will 
cause hard extraction and may 
cause the cartridge case to stick in 
the chamber sufficiently to cause 
failure to extract. Barrels with 
chambers having pits large enough 
to cause cartridges to stick are 

(g) All rebuilt carbines must be coun- 
terbored at the muzzle end of the 
barrel (Fig. 79). This counterbore 
improves the accuracy of the car- 
bine and is intended to eliminate 

tool marks, nicks, and burrs in the 
muzzle end of the barrel. 

(h) Barrels of current manufacture have 
been modified by the elimination 
of a portion of the skirt on the 
chamber end. In barrels of early 
manufacture, this skirt was ex- 
tended around approximately two- 
thirds of the chamber end of the 
barrel and was thickened some- 
what in its center section. As the 
thin section of the skirt served no 
useful purpose, it was eliminated 
and only the thickened portion 
remained. When looking into the 
breech end of the gun only the 
thickened portion remained. When 
looking into the breech end of the 
gun ahead of the bullet ramp, the 
thread of the receiver can be seen 
(Fig, 80). This is a normal con- 

(0 In well equipped establishments 
where it is practicable to perform 
barrel straightening operations, the 
barrels may be straightened if nec- 
essary to meet targeting require- 
ONLY). Barrels that are rejected 
because they do not meet targeting 

Figure 77. Removing piston nut from gas cylinder. 




requirements but are otherwise 
serviceable, should be retained in 
the depot maintenance shop until a 
sizable quantity has accumulated, 
whereupon disposition instructions 
should be requested from Chief of 
Ordnance, Washington 25, D.C., 
ATTN: ORDFM. The use of drop 
plug gages to check the straightness 
of the bore is not required. How- 
ever, if the depot maintenance 
establishment performing the work 
deems it practicable, such gages 
as shown on drawing B7317562 
are authorized for use in process 
inspection, local fabrication, and 


Check to see that the new type 

front band assembly (Fig. 81) is 
used and that the rivets are tight. 
Visually inspect bayonet stud on 
front band to assure that it is in 
good condition. Modification Work 
Order ORD B28-W5 specifics that 
the old type front band assemblies 
must be replaced with the new type 
{Fig, 81) and describes the pro- 

cedure. Check shape of front band 
swivel to assure that it swivels 
c. Gas Cylinder Group. 

(1) Inspect the swaged-on type cylinder to 
assure that it is tightly swaged onto 
barrel, as determined by a hand test. 
Check all gas cylinders for deformation, 
piston wear, burrs, carbon, and rust, 
and check the gas port for foreign 
matter, using a 0.070-inch drill or plug 
inserted by hand. 

(2) Inspect piston for wear, burrs, and 

(3) Inspect piston nut for loose fit in gas 
cylinder. Inspect threads and turning 
lugs for wear and burrs. Inspect piston 
aperture for burrs. Piston should be an 
easy fit in aperture. Examine to deter- 
mine that the gas cylinder has been 
staked very lightly into the nut in one 
place only. 

(4) Check carbines M2 and M3 to assure 
that only the counterbored piston nut 
is used. In the carbine Ml and M1A1, 
either the counterbored nut or the 
earlier type without the counterbore 





A- top view 


. ■'" ■ ■ ■ 








operating shoe .k6m6v& cut 




RA PD 914*9 

Figure 78. Barrel and receiver group — points of inspection. 



- •■: 

(A PO ?1«50 

Figure 79. Muzzle end of barrel showing 

is usable; if a carbine lacks power with 
the uncounterbored nut, replace with a 
counterbored type (Fig. 43e). 

(5) After the piston and nut are assembled 
in the gas cylinder, check to assure that 
there is no binding. 

(6) Inspect receiver for looseness with 
barrel, deformation, rust, and burrs. 
If receiver is disassembled from barrel, 
inspect for worn or crossed threads in 
barrel aperture. 

d. Check Chamber for Proper Head Space 

(Page 50). 

Note When using the head space gage, dis- 
engage the bolt from the operating slide. There 
are two types of head space gages assigned the 
same stock numbers for same sizes. If the gage is 
of the design that has a rim, place the rim care- 
fully under the extractor against the face of the 
bolt (Fig- 83), if the extractor is assembled, there- 
by avoiding snapping the extractor over the gage. 
When the other type (shouldered), is used, it is 
inserted into the chamber first and the bolt closed 
on it. In closing the bolt to check the depth of the 
chamber, exert only the lightest finger pressure and 
make sure that the hammer does not exert pressure 
against the bolt. 

(1) Insert head space gage 7319934 (head 
space length 1.290 inches) into cham- 
ber, wide cylindrical end first, and 
close bolt. The bolt must close on the 
gage. With a new barrel, the bolt may 
not close on the gage without being 
forced. This is an indication that the 
head space is insufficient and the 
chamber must be reamed. 

(2) Insert head space gage 7319938 (head 
space length 1.298 inches). If the bolt 
closes without perceptible bite on the 
gage, the carbine is not acceptable for 

return to stock. 

(3) Field test bolt 7819982 (instead of 
carbine bolt) must close on head space 
gage 7319934 (head space length 
1 290 inches). This is necessary to 
assure interchange ability. The field test 
bolt is dimensioned 0.560 inch from 
face to locking surface. 

(4) When the carbine is rebarreled (DEPOT 
MAINTENANCE ONLY), every effort 
must be made to hold the head space 
as close as possible to 1.290 inches, 
using the field test bolt. Under no 
circumstances should head space ex- 
ceed 1.295 inches on rebarreled car- 
bines, using head space gage 7319936 
with the field test bolt. 
(5) Carbines whose head space is less than 
1.302 inches, that is, component bolt 
does not close on head space gage 
7319943 are acceptable for domestic 
and overseas use (FIELD MAINTE- 

Figure 80. Breech and barrel showing new type 



e. Inspection After Assembly of Barrel and 
Receiver Group. After assembly of the barrel and 
receiver group, perform the following inspections: 

(1) Check to assure that barrel has been 
staked at rear end of front sight. 

(2) Check to assure that staking the front 
sight key way and the application of the 
proofmark have not distorted the bore. 

(3) Check front band screw to assure that 
head is in good condition and that it is 
staked or spun over sufficiently to 
prevent loss of screw. 

(4) Check to assure that the ring portion of 
the front band surrounds the barrel 
with spring tention and check the 
swivel to assure that it swivels properly. 

(5) Check to assure that the operating slide 
can be drawn all the way back to its 
stop against the receiver without 





<l Chasing Gas Cylinder Thread. Chase threads 
of the gas cylinder, using gas cylinder tap member 
of tool 7160995 (Fig. 83). Dip tap in a cutting oil 
and start tap carefully in gas cylinder. Cut threads 
a little at a time, using a forward and backward 
movement. Exercise care to stop tap as soon as it 

fiAHD. WONT. AUV**9t7ft60 


VP'm** »A»!J0IWA 

Figure 81. Front band assemblies. 

KMT CtOirUb OH 1 .1M CAM 

Figure 82. Checking head space. 

touches bottom to prevent damaging tap or cyl- 
inder. Remove tap and thoroughly clean chamber. 
b t Carbon and Rust 

(1) Carbon. Because of the rearward 
position of the gas port and high gas 
pressure encountered there, excessive 
carbonization of cylinder and piston 
is unlikely. However, these parts should 
be cleaned at regular intervals, or when 
fouling or sticking of piston is evident; 
the gas port in the barrel should be 
inspected and cleaned if necessary. 
Remove piston nut and piston from gas 
cylinder and scrape excess carbon off 
with flat blade. Take care not to 
scratch parts unnecessarily. When car- 



■ ■ • ■ ; ; ■ ■ ■ ■ . : L ; 

r ' ' \ * V\ : ■ L . 

■ * 

■T ■ ■ * 




L ' L ' 1 I T 


Figure 83. Chasing gas cylinder thread. 

bon has been removed, clean inside of 
cylinder and piston, oil very lightly and 
replace. Clean gas port with an 0.070- 
inch or smaller drill inserted by hand, 
or with piece of wire or similar instru- 
ment. Be sure to stake piston nut 
lightly in place when assembling. 

Note. Pistons, breech end of receivers, 
and other parts subjected to burned 
powder must be thoroughly cleaned. 
Scrub these parts with a bristle brush 
moistened with rifle-bore cleaner. 

■ ■ . ' / : .. . .; . ,.. 

■ : - 

. :-lW' 

Figure 84. Reaming chamber for head space. 

(2) Bust Rust is more likely to form on 
surfaces not regularly lubricated, or 
where barrel head dissipates oil film 
rapidly. Such points are under side of 
barrel, body of oiler beneath sling, 
receiver locking lug recess in recoil 
plate, operating slide spring, well in 
receiver ("alternate" design receiver) 
or spring housing tube, rear sight base, 
inside faces of operating slide, recesses 
in trigger housing, and unexposed 
recesses and faces. Remove rust with a 
rag saturated with rifle-bore cleaner, 
preservative lubricating oil (special) 
or by using crocus cloth, but exercise 
care to avoid scratching surfaces. After 
rust is removed, wipe surface with 
clean, dry cloth and then with clean 
cloth lightly saturated with preservative 
lubricating oil (special). The operating 
slide spring housing (or tube) may be 
cleaned with the carbine cleaning rod 


. - 


■ ■■:: : , ■ 


■ . ■■ 

' XL 

■ . ■■ '■ .. 

■ ■ ■ ■■ 

..'.• ... ■ 

QUtfTIOhAlUl Mfttftt NilMBS* 

^**#- ■ fi.tHiw*™™^ 

.•l-sSPW 12 

■im ' 

';:.■.. "■:■■.■■ " 

mm »«w 

Figure 85. Serial numbers on cat. .30 carbines. 




;ra po i wwa 


Figure 86. Relocated serial number on cal. .30 

and small patch. Be sure rear end of 
tube is clean. 

c. Refinishing of Barrel and Receiver. When 
necessary to sand or grit blast ki remove rust or 
otherwise prepare the barrel and receiver for re- 
finishing, remove the rear sight and front band. 
If practicable, the front sight should be kept mated 
with the barrel and receiver assembly from which it 
is removed. When original finish is reasonably 
satisfactory, the removal of front and rear sights 
and the front band to permit sand blasting, in 
order to obtain the highest quality protective 
finish, is not required. During any refinishing 
of the barrel and receiver, the gas cylinder, muzzle, 
and breech end of the barrel must be plugged with 
corks to prevent solution from entering the bore 
or the cylinder portion of the gas cylinder. By 
drilling a 3/16-inch hole through the rear end of 
the receiver into the operating slide spring hole, 
good circulation of phosphating solutions and 
preservative compounds can be obtained. 

d. Reaming Chamber. 

(1) Dip breeching space reamer 7319906 in 
lard oil and place in chamber through 
top opening of receiver (Fig. 84). Turn- 

ing handle slowly to the right, remove 
only sufficient metal to permit bolt to 
close on head space gage 7319934 
(head space length 1.290 inches). 

(2) Wash chips from reamer and chamber 
with lard oil after removing from 

(3) Handle reamer with care to prevent it 
from being chipped or picked. Never 
turn reamer backwards in chamber as 
this tends to dull the cutting edges. 

e. Restoring Serial Numbers (FIELD MAIN- 
TENANCE). Serial numbers which have become 
obscured because of the installation of the ad- 
justable rear sight must be restored. Since the 
degree of obscurity varies, this will be effected in 
one of two ways: (1) if the serial number is ques- 
tionable (Fig. 85) (one digit obscured), use white 
graduation fUler 52-F-l 00-230, listed in Depart- 
ment of the Army Supply Catalog ORD 3 SNLK-1, 
to improve the legibility; and (2) if the serial 
number is obscured (Fig. 85), it will be relocated 
on the receiver bridge directly forward of the rear 
sight platform (Fig. 86). 

(1) Questionable serial numbers (FIELD 
(a) Mask the adjustable rear sight 
to prevent filler from entering the 
(6) Work a small quantity of filler into 
the serial number and allow it to 
dry for 5 minutes. Wipe off all 
excess filler with a clean rag and 
allow to dry for 3 hours. 
(c) In the event that the application of 
filler fails to restore the legibility 
of the serial number, relocation of 

L ■ '■ ll "" ■ ' ■ ' L ■ -'' L * ■' ". '■' 



Figure 87. Placement of barrel and receiver as- 
sembly in vice-held stamping fixture. 



the number by depot maintenance 
personnel is required. 
(2) Obscured serial numbers (DEPOT 
organizations engaged in restamping 
serial numbers will fabricate fixtures 
locally to reinforce and clamp the 
receiver during the stamping operation. 
Two fixtures have been developed for 
this purpose; the vise-held stamping 
fixture (Figs. 87 and 88) and the 
bench-mounted stamping fixture (Figs. 
89 and 90). The choice of fixture 
which best suits the requirements of 
the maintenance organization is left 
to the discretion of that organization. 
(a) Vise-held stamping fixture. This fix- 
ture is relatively simple to fabricate 
requires little space for storage, 
and may be quickly mounted in 
any vise. However, it is not adapt- 

%«> M«fM 

Figure 88. Vise-held stamping fixture with barrel 
and receiver assembly in place. 

-■ ; ' ■ . . . ■-' ! 



:.:■:■■:■■ ■ ■ 

. ■ 

able at maintenance installations 
where large quantities of carbines 
are to be restamped, since the 
carbines must be disassembled be- 
fore relocation of serial numbers 
can be accomplished. 
(b) Restamping with vise-held stamping 


1. Secure fixture firmly in vise as 

shown in figures 87 and 88. 

2. Clamp the barrel and receiver 
assembly in the fixture (Figs. 
87 and 88). 

Note. The fixture is so designed 
that disassembling the barrel and 
receiver assembly is not required. 

3. Manually position and space the 
3/32-inch stamping fixture on 
the bridge of the receiver directly 
forward of the rear sight plat- 
form (Fig. 86). Strike the stamp- 
ing fixture with one firm blow of 
the hammer to insure a neat and 
distinct impression. Repeat this 
procedure until all digits of serial 
number are transposed. 

Note. The 3/32-inch stamping 
fixture is not included in the 
supply system and must he 
procured locally. 

"Pi ; 'T^' : 


Figure 89. Carbine clamped in bench-mounted 
stamping fixture. 

Figure 90. Bench-mounted stamping fixture with 
carbine and stamping figure in place. 



4. Use white filler as prescribed in 
(1) above to increase legibility. 

Note. Under no circumstances 
will the original serial number be 

5. Upon completion of the stamp- 
ing operation, assemble the car- 
bine and operate through the 
complete firing cycle to deter- 
mine whether the receiver has 
been deformed. 

(c) Bench-mounted stomping fixture. 
This fixture is especially useful at 
depot maintenance installations 
where large quantities of carbines 
are to be restamped because only 
the removal of the bolt from the 
carbine is required before clamping 
the carbine in the fixture. Further- 
more, positioning and spacing of 
the stamping fixture is accomplish- 
ed mechanically. 

(d) Restampimg with bench-mounted 
stamping fixture. 

L Secure the fixture to the bench 
or table by inserting bolts 
through the holes, provided for 
this purpose, in the base of the 
fixture. Allow sufficient clear- 
ance for the unobstructed in- 
sertion of the carbine in the 


Figure 91. Assembling barrel to receiver. 

*A fl) *U59 

Figure 92. Checking barrel and receiver alignment. 

2. Remove the bolt from the car- 
bine and clamp the carbine in the 
fixture, as indicated in figures 
89 and 90. 

3. Place a 3/32-inch stamping fix- 
lure (Fig. 90). Position and space 
the stamping fixture by adjusting 
the stamping guide. Strike the 
stamping fixture with one firm 
blow of the hammer to insure 
a neat and distinct impression. 
Repeat this procedure until all 
the digits of the serial number 
are transposed. 

Note. The 3/32-inch stamping 
fixture is not included in the 
supply system and must be 
procured locally. 


Upon completion of the stamp- 
ing operation, install the bolt in 
the receiver and operate through 
the complete firing cycle to 
determine whether the receiver 
has been deformed during the 
stamping operation . 

Note. Under no 
will the original 
be obliterated, 

serial number 


Inspection. All carbines will be 
inspected to insure that the re- 
located serial number is a duplicate 
of the original serial number. 
/. Counterbore Muzzle. 

(1) The muzzle of all barrels must be 
counterbored (Fig. 78) during re- 
rebuild to remove tool marks, nicks, 



and burrs in the muzzle end of the 

(2) The depth or diameter of counterbore 
will be determined by the amount of 
blemishes to be removed* 

(3) All barrels will be counterbored slightly 
during rebuild, even though there is no 
visible blemish. 


a. Replacing Barrel. Select proper barrel and 
receiver combination so that about 1/16-inch draw 
is obtained when assembled. Screw the receiver on 
the barrel with receiver and barrel wrench 7113308 
draw up receiver until alignment marks on barrel 
and receiver (Fig. 91) coincide. Then determine 
that the flat surfaces on bottom of barrel and 
receiver are parallel. Check this by indicator or 
placing two bars, about 10 inches long, in position 
as illustrated in figure 92; and sight over the 
edges. When the two bars lie parallel, the barrel 
and receiver are in exact alignment for proper 

Note. After installing barrel on receiver, ad- 
just and check the head space as described on 

pages 82 and 85. 

b. Gas Cylinder Piston and Nut. Insert gas 
cylinder piston into cylinder and screw cylinder 

piston nut into the threads using gas cylinder 
reconditioning tool 7160995 (Fig. 83) (with 
component wrench). Make certain to stake the 
cylinder lightly into the nut, in one of the three 
places provided, or the nut may work loose during 
the firing of the carbine. After the piston and nut 
are assembled in the gas cylinder, check to assure 

that there is no binding {page 82). 

Ml, M2, AND M3 


a Front Band Locking Spring (Figs. 93 and 
94). Insert small, straight punch in spring spindle 
hole in left side of forward end of stock and drive 
out front band locking spring part way, from left 
to right; then rotate spring and pull from hole. 
&. Recoil Plate (Figs. 93 and 94). 

(1) Inscrew recoil plate screw counter- 
clockwise until clear of escutcheon 

threads (above % inch), then withdraw 
from stock and recoil plate. 

(2) Loosen recoil plate by tapping lightly 
on rear top face with a metal tool. 
Pull plate directly forward out of 
seating recess in stock. Do not pull up 
or down, because rear seating lug on 
plate seats in a horizontal recess cut in 
the stock. 

(3) Do not remove the recoil plate screw 
escutcheon from the stock except for 
replacement. To remove, thread recoil 
plate screw into the escutcheon from 
the underside until all of the threads of 
the escutcheon are engaged and pull 
escutcheon out of stock. If withdrawal 
is difficult, insert small straight punch 
from top of screw hole in stock and tap 
end of screw lightly to loosen es- 
cutcheon, or thread screw in from top, 
part way, and tap lightly; then proceed 
as above. 

c. Butt Plate (Figs. 93 and 94). Unscrew butt 

plate screw counterclockwise and remove from 
stock. Loosen butt plate by tapping it lightly. 
Pull to rear off stock. If butt plate is tight, do not 
pry off, as stock is likely to be damaged. Tap on 
edges lightly all the way around, until loose enough 

to pull from stock. 

d. Hand Guard {Figs. 93, 94, and 96). The 
liner of the hand guard assembly is riveted to the 
hand guard; do not remove it. 


a. Stock. Inspect stock for cracks, scoring, 
chipping, blemishes, and excessive dryness. Inspect 
cuts and apertures (Fig. 95) for chipping and burrs, 
for wear due to interference with moving parts, 
and for excessive friction in assembling. 

b. Butt Plate. 

(1) Inspect butt plate for deformation, 
burrs, fit, and looseness on stock. 
Check butt plate screw for looseness 
and check threads in stock for strip- 
ping. The butt plate screw must fit 
firmly in stock. 

(2) Protrusion of butt plate beyond edge of 
stock is acceptable in rebuilt weapons 
unless more than approximately one- 
half of the thickness of the metal 
extends beyond the edge of the stock. 

c. Front Band Locking Spring. Inspect front 
band locking spring for deformation and excessive 



. : ■ 

urn t*i (» -<-■ » - .. w..-— — " **A 

Figure 93. Stock and guard assemblies - carbine 


■■'■'■ ■ ■ L ■ 

1 ^*|l f «HMH-»H^0 






■ r , : ■ 


nvM»ai*«« MMiNi ■ 


Figure 94. Stock and guard assemblies — carbines 
M! M2and M3. 

wear of locking shoulder. Rear face of shoulder 
should be square enough to retain front band in 

d. Clearance Cuts. Although the same stock is 
used on carbines M2, M3, and late model Ml, for 
the M2 and M3 examine clearance cut on right for 
disconnector and disconnector lever, and clearance 
cut on left side for selector (Fig. 97). There must 
be no binding of either due to undersized cuts. 

& Recoil Plate. Check to assure that recoil 
plate is free from burrs, excessive wear (Fig. 104) 
and rust, and that it is properly bedded in stock. 
Where recoil plate is bedded so deeply in stock that 
it interferes with proper alignment of action, the 
stock must be rejected. The recoil plate screw 
escutcheon should not turn in the stock, have 
burrs, or worn threads. The screw should be 
tightened firmly. 

f. Fit of Action. Check fit of action in the 
stock. Clearance between recoil plate and receiver 
should not exceed 0.0005 inch when checked with 
a feeler gage (DEPOT MAINTENANCE ONLY). 

See figure 98 for old and new type recoil plates. 
Both designs are usable if otherwise serviceable. 
Insert the recoil plate lug on the receiver into the 
recoil plate. With a slight pressure tending to push 
the barrel in the stock, rap the butt end sharply; 
the action should snap into place. The action then 
should be suspended by the recoil plate with 
clearance under the receiver and barrel. Test the 
action for longitudinal play. If such play exists or 
the action does not lie properly in the stock, a 
new stock assembly should be selected or the recoil 
plate replaced in order to meet the above re- 
quirements. This is particularly necessary in order 
to avoid injury to the stock assembly when the 
spring type recoil plate is used. 

8- Trigger Housing Clearance. Check to assure 
that there is at least 0.010-inch clearance between 
rear end of trigger housing and stock. Use a feeler 



i>wi*lf*> fci 


Figure 95. Stock showing apertures - carbine M1. 

* ■ ■ lt 

«-fA*c«. •***»-« . 




Figure 96. Stock and hand guard - carbine Ml. 

i UC-* .'if' 



Figure 97. Stock and hand guard - carbines Ml 
(lata), M2andM3. 



/?. Hand Guard Liner. Check to assure that 
liner in hand guard assembly is not distorted and is 
securely fastened to hand guard. Liners with two 
rivets or with four rivets, if serviceable, may he 
used on carbines Ml and M1A1. Only the four- 
rivet type hand guard assembly 6212602 is to be 
used on the carbines M2 and M3 (Fig. 99). 

i. Hand Guard. Check hand guard to assure 
that front end, which is engaged by front band, is 
in satisfactory condition. The lengthwise fit of 
the hand guard should be sufficient to assure 
adequate engagement with the front band and the 
hood of the receiver. 

;. Oiler. Inspect oiler to assure that new type 
neoprene washer is installed. 


a. Binding of Parts with Stock, 

(1) Binding of moving parts with stock or 
lack of proper clearance for assembly is 
evident on the stock by rubbed areas. 
Relieve such binding points by filing or 
paring, using fine file or sharp, flat 

(2) Relieve friction due to swelling caused 
by excessive moisture only enough to 
allow proper functioning and/or as- 
sembly, as wood may later dry out and 
shrink. Use of raw linseed oil will help 
to prevent undue swelling of wood due 
to excessive moisture. 

(3) Points to check for excessive friction or 
lack of sufficient clearance are — 

(a) Aperture in stock for trigger 
housing (Figs. 96 and 107). There 
must be a minimum of 0.010-inch 
clearance between stock and the 
rear if the trigger housing. Less than 
0.010-inch clearance between stock 
and trigger housing causes the 

RAPO 1 1 Ml 3 

WW TfPt 


Figure 98. Recoil plate 5557150 - old and new 
type (both types usable). 

»A *0 DOW/* 

Figure 99. Hand guard assembly 6212602. 

shock of recoil to be transmitted 
to the trigger housing retaining pin. 
This is especially detrimental in the 
case of the carbines M2 and M3. 

(b) Left inside face of stock opposite 
head of hammer pin. This face may 
be scored because of an incorrectly 
assembled hammer pin. 

(c) Point on right side of stock and 
hand guard where operating slide 
bar passes through to right side of 
receiver (Fig. 95). 

(d) Recess in bed of stock in which 
operating slide functions (Figs. 97 
and 106). 

(e) Forward shoulder of stock and 
hand guard where front band seats 
(Figs. 96 and 107). 

if) On the carbines M2 and M3 the 
left-hand side of stock where 
selector is Located and the right- 
hand side of stock where dis- 
connector lever assembly is located 
(Fig. 97). 

b. Loose Rivets in Hand Guard Liner. * A 
hand guard liner (Figs. 93 and 94) indicates im- 
proper spreading of the rivets. These rivets are 
tubular; tighten them by spreading the hollow 
(inner) ends with a blunt punch. Support the 
opposite (beaded) end of the rivet while riveting. 
Place rivet head on a small steel rod or punch 
clamped in a vise. 

c. Front Band Does Not Seat If the front 
band does not seat properly behind the shoulder 
of the front band locking spring when assembled, 
Hie seating shoulders on stock or hand guard are 
not cut back far enough or the hand guard liner 
is too long. To remedy this condition, file the 
shoulders of stock or hand guard or both at the 
front sufficiently to allow proper seating and 



Figure 100. Patched stock- 
locking of band. Use a fine flat file with a safe 
edge and file rear face of shoulder only. Do not 
file the hand guard liner* for if it is too short the 
hand guard will fly off when firing the carbine. 

d. Patching and Repairing Stock (DEPOT 

(1) Dents. Sand out dents or mutilations 
that do not affect strength or general 
appearance; use wood dough if prac- 

(2) Cracks. Components which are cracked 
in such a manner that strength is 

affected must be replaced. Where the 

strength is not affected, use repair 
screw A233523* or similar screw 
machined from brass to reinforce weak 
areas and small cracks. Drill an 0.081- 
inch hole to receive screw (Fig, 101). 
Install screw by gripping it in chuck of 
a hand drill. Cut off screw and file 
flush with stock so that no edges 
protrude. Wherever possible dovetail 
patches in. In figure 100, the light- 
colored patches show areas that may be 
patched and the method of inserting 
them in the stock; the dark-colored 
patches show areas that cannot be 
patched without weakening the stock. 
(3) Stripped thread for butt plate screw. 
It the butt plate screw cannot be 
tightened properly due to stripping of 
threads in the stock, bore a hole of 
approximately one-half inch diameter 
in the stock to a depth approximating 
length of the screw and obtain a !^- 
inch hardwood plug (hickory or wal- 
nut) which is a drive fit in the stock. 
Apply glue (adhesive — JAN-A-397) to 
the hardwood plug and the bored hole 

5£— ' ' 

n ' 

■ ■ ■: ■■■ ':,■'- " 

■■■..■ t 



W ■ d: •■• 

■ : ■■ 



-.-. ■ . 


■■:: ,. 

: ■ 

■ ■ ■ 

■ : \,r ::: - : 

\[ ' ' ■ L L ' ' 

■ ■■■■;:'. 

■ ■ >-[*'•'- • 


■:■;. ■ : . ■ ...■■■.-■■ ■ ; 
■: ; : : ■■' '; :-'• k 

: ■ ■ ■■■■:-:- : 
, ■ 


Figure 101. Installing repair screws. 



RAPD 1I5216A 

Figure 102. Repair for stripped screw hofe. 

in the stock. Drive the plug into the 
bored hole (Fig. 102). 
e. Stock Modification. Carbine Ml stocks of 
stock assemblies C57157 of early manufacture 
were made with a thin section on the right side 
where the operating slide bar passes to the right 
side of the receiver. This thin strip should be re- 
moved in order to prevent cracks from starting in 
this area The stock should be cut down as shown 
in figure 103. 


a. Front Band Locking Spring. Insert spindle 
of front band locking spring into hole in right for- 
ward end of stock and drive to the left. Seat spring 
fully in recess in stock- 
Note. Bore out oversize (approx. 3/8 in-). 

Glue and drive in hardwood dowel plug and rebore 
and countersink proper size hole for butt plate 

b. Recoil Plate. 

(1) If escutcheon has been removed, insert 
small end first in seat in lower face of 
stock grip. Tap in until seated level 
and flush with stock. 

(2) Insert recoil plate into rear of receiver 
aperture in stock with bevel face up 
and tang to rear. Recoil plate must be 
inserted from front to rear and held 
level during insertion, so that seating 
lug and horizontal recess will mate. 
Seat recoil plate evenly and flush with 
recess in stock by tapping lightly. In- 
stall recoil plate screw through top of 

recoil plate and stock grip, thread into 

escutcheon, and draw down part way. 

Then assemble barrel and receiver 

group to stock, align, and draw screw 

down tighL This prevents a strain on 

operating parts. 

c. Butt Plate. Plate butt plate on butt and tap 

lightly until solidly and evenly seated on butt. 

Insert screw and turn down snugly. Do not force 

screw as threads in wood of stock may strip. 



a Stock Extension (Fig- 105). 

(1) Remove lower hinge screw from lower 
end of stock grip by turning counter- 

(2) With stock extension in extended 
position, unscrew the hinger screw 
projecting from the upper face of 
the recoil plate cap by turning counter- 
clockwise. When screw is disengaged 
from the lower hinger nut, pull screw 
up and out of grip and then lift off 
recoil plate cap and lower hinge. 

(3) With flat-ended punch, push hinge 

screw spacer out of hole in the lock 

on end of lower bar up into coil spring. 

Then pull stock extension to rear from 

stock and remove grip spring, hinge 

screw spacer and trip spring washer 
from countersunk hole in lower end of 

grip. Take care that spring does not 

fly out or washer does not become lost. 

(4) Remove grip and recoil plate by un- 
screwing the grip screw counterclock- 
wise from top of recoil plate. 


cl Inspect corresponding parts of stock as for 
carbines Ml, M2, and M3 (Figs. 106 and 107). 

Refer to page 90, 

b. Inspect grip for looseness on stock and for 
cracks. Grip should be rigid with stock and no 
twist should be possible when assembled. 

c. Inspect stock extension for smoothness of 
hinge action and positive locking when extended 
and when folded. The extension should be rigid 
and without shake when extended with butt plate 
rigidly at right angles to the bars. When swung to 
the left, the lock should cam out of the slot 



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Figure 103. Modification of stock D44007 of early manufacture (carbine M1). 

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tockiKG ivo OF 


i 'APES 30 MG 

KATE. RCCOIl-«a5/*l* 


<MCf S StOW OUI 30 DfO 

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Figure 104. Important wearing surfaces. 




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Figure 105. Stock assembly 6544072 and hand 
guard assembly 6212602 for carbine M1A1. 

deepen grip screw hole to a total depth of 1.125 
inches with drill (diameter 0.159-inch). Inspect 
routed threads in grip for wear and stripping. 
Screw should turn in snugly to retain recoil plate 
and grip. If screw is loose, routed threads will 
eventually strip out and grip will twist loose. 

ft. Inspect grip spring washer and hinge screw 
spacer for deformation. Spacer should fit in hole 
in lock on lower bar when assembled. 

j. Inspect locking nut for looseness in lower 
hinge shell. Inspect shell for deformation. Inspect 
sling eyelet for looseness on hinge shell (Fig. 104). 
(Nut is staked or spot-welded in shell and eyelet 
spot- welded to shell.) Check locking slot in nut for 
wear and burrs (angle of slot face is 30 degrees). 
Inspect lower hinge screw for wear and inspect 
threads in grip for stripping. 

in the locking nut, and the extension should 
pivot smoothly about the hinge screw through an 
arc of approximately 180 degrees to lie flat against 
the left side of the stock. When the extension is 
pressed flat to the stock, the lock should slip 
into the slot in the locking nut and the butt plate 
should pivot on the bar ends, so that the extension 
will lie locked close to the stock without looseness 
or shake. If shake is present in either position, a 
worn locking lug or locking nut, a loose hinge 
screw, or a broken hinge spring is indicated. If 
pivoting is jerky, or binding is apparent, burrs on 
locking lug or in slot of locking nut or bent bars 
are indicated. If butt plate is loose on bars or 
fails to pivot under spring tension, burrs or a 
damaged butt plate spring are indicated. 

d. Inspect recoil plate cap for dents and fit 
with rear end of stock. Plate should lie flush at the 
edges with the stock and receiver. 

e. Inspect recoil plate for security and level 
seating on stock. Plate should seat level and firm 
on stock, held down by grip screw passing through 
plate and stock and into routed threads in grip. 
When assembled, the grip screw holds all three 
parts together. The hinge screw, when assembled 
and threaded into the nut, binds the parts still 
tighter and prevents the grip from twisting. 

f. Inspect receiver locking lug seat in recoil 
plate for wear and burrs (Fig. 104). When as- 
sembling, the locking lug on receiver should cam 
smoothly into the seat and be held there snugly 

without play or shake. 

g. Inspect grip screw for length and burred 
threads. Replace the 2 3/32-inch grip screw by a 
2 3/4-inch screw. If screw has not been replaced. 

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Figure 106. Stock and grip for carbine M1A1. 

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Figure 107. Stock, hand guard and grip for carbine 



j. Inspect hinge on upper bar for deformation 
and cracked welding and lock on corresponding 
end of lower bar for deformation, cracked welding, 
and wom locking lug (Fig. 104). The proper 
mating of lock and nut determine the rigidity of 
the stock extension when extended or folded. 
Angle of lock faces should correspond to that of 
the nut. Wear of lock or nut will cause looseness 
and improper locking. 

k. Inspect bars for deformation. They should 
lie in the same vertical plane when assembled. 

/, Inspect butt plate for smooth pivoting on 
rod ends, for spring action with spring assembled, 
and for cracks. Inspect butt plate spring for ten- 
sion, excessive deformation, and broken or bent 

m. Inspect cheek rest plate and retaining plate 
for deformation and looseness with each other on 
the bars when assembled. Inspect rivets for loose- 
ness and protrusion of heads. Inspect cheek rest 
cover for scoring and cracking of leather. Cheek 
rest plate should be held tightly to bars by re- 
taining plate and rivets, and leather cover, on the 
stock extension assembly (Fig. 105), should be 
smooth, so it will not scrape face of operator. 


a. When the stock for the M1A1 carbine is 
irreparable or unavailable, it is to be replaced by 
the standard type stock assembly for the carbine 

b. For maintenance and repair of wooden 
components, see page 92 covering the carbines 
Ml, M2 and M3. 


a. Stock. For items that correspond to the 
carbines Ml, M2 and M3, see page 94. 

b. Stock Extension. 

(1) If the grip and recoil plate have been 
removed, replace them by fitting grip 
to rear, under face of stock, just behind 
trigger guard opening so that pro- 
jection on grip points downward and 
trigger guard bow will fit into forward 
face of grip when assembled. Seat the 
recoil plate on top of rear end of stock 
with undercut lug facing forward. 
Align screw holes in plate and stock, 
insert grip screw and screw down 

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Figure 108. Removing magazine base and follower. 

tightly, turning clockwise to secure 
recoil plate, stock, and grip firmly 
(2) Place grip spring washer in large coun- 
terbored hole in lower end of grip 
and seat grip spring in hole upon 
washer. Then grasp stock extension so 
that locking lug on lower bar faces 
downward and place upper face of lock 
against lower end of grip spring. Hold 
in position firmly and pross upward on 
lock against spring pressure until hinge 
on upper (straight) bar will slip over 
and lie upon top of recoil plate. Still 
holding lock in position with regard to 
spring, align hole in spring and lock, 
and insert hinge screw spacer until 
flush with lower face of lock. 


VI. Final Inspection 


Weapons turned in for repair may be assumed 
to have defects caused by use or neglect. When 
they were accepted as new weapons, the parts 
composing them were dimensionally correct and 
made of the proper material. Consequently, the 
inspection of these weapons after repair will differ 
from the inspection procedure used in the manu- 
facturing plant in that attention will be directed to 
wearing surfaces, parts that might crack or break 
due to high stress or fatigue, and evidence of 
corrosion. These defects do not evidence them- 
selves by uniform reduction in a given dimension 
but show up as a chipped edge, a partially worn 
surface, or an eccentric hole. A gage used in 
manufacturing is merely means of comparing an 
unknown dimension with a known one to judge 
whether a piece comes within tolerances. After a 
piece is worn through use, the change in dimension 
is more easily detected in many cases by comparing 
with adjacent surfaces; the piece in itself becomes a 
gage. Visual inspection, therefore, is far more 
applicable in these cases and gaging is limited to 
those dimensions that are critical and that may be 
advantageously measured rather than compared. 
Inspection of noncriticai parts (parts that do not 
cause malfunctions) is limited to appearance and 
the presence of cracks or flaws. The dimensions 
placed on these parts (and gaging used during 
manufacturing) were for the sole purpose of 
insuring interchange ability. Even if the dimension 
of such parts are worn considerably below drawing 
tolerances, functioning and interchangeability will 
not be adversely affected and the parts are conse- 
quently acceptable. 


Table II is a check list for inspecton of the 
carbines in the hands of troops and is applicable 
to check points of inspection for return to user and 
for return to stock. 


a. Carbines are not to be considered un- 
suitable for oversea use because of lack of modi- 
fication unless such modification affects the safety 
of personnel, is essential to the functioning of the 
weapon, or is prescribed by an URGENT modi- 
fication work order. 

b. Newly manufactured and issued materiel, 
which has been inspected and accepted in ac- 
cordance with Department of the Army speci- 
fications, is not to be rejected except for well- 
grounded reasons. All such rejections must be 
reported immediately to higher authority. 

c. Satisfactory metal finishes for weapons 
range from dense black to medium light gray. 
Certain small-arms weapons are manufactured 
with an unusual shade of neutral gray finish. 
Since this finish (gray zinc phosphate) is an ac- 
cepted Department of the Army standard, these 
weapons are not to be rejected by inspectors or 
troops for this conditon. A worn surface is ob- 
jectionable from the standpoint of visibility when 
it is capable of reflecting light, somewhat as a 
mirror does. No weapon is to be rejected for over- 
sea use unless exterior parts have a distinct shine. 
Bright rear sights must not be permitted on weap- 
ons for oversea use. Check to see that all rear 



sights have a dull black or gray finish on all sur- 

d. Wooden components must not be cracked 

in such a way as to interfere with their structural 
strength. Surface cracks, bruises, or dents which 
do not affect their strength should not cause 

e. Inspection of the barrel to determine that 
it meets the requirements for return to user is 
similar to the inspection of the barrel required for 
return to stock which is described in TB ORD 366. 

f. Looseness and play in such components 
as the sight, gas cy liner, recoil plate, bolt, may be 
cause for rejection. In many cases, however, the 
importance of such defects is exaggerated. Loose- 
ness and play must be considerable to affect the 
accuracy of a weapon beyond its natural dis- 
persion. All weapons, especially those that are 

t*vi.C^»i»i»+.ic^, muai hnvr pl»y hotwOfilT. "WOrkillg 

components to permit them to operate in localities 

where sand and dust are prevalent. A weapon may 
be completely useless if its working parts are fitted 
with insufficient clearance. 

g. Minor defects in metal components do not 
normally affect their being acceptable. Scratches 
and tool marks on barrels are ordinarily of no 


h. Inspect the functioning and operation of 

components as desribed. 

I Check to see that serial number on receiver 

is plainly visible. 



25-yard range targeting diagram for carbines, 
cal .30, Ml, M1A1, and M2. 

Note. It should be understood that in processing 
inspection (as distinguished from final inspection), 
the adjustment of windage is accomplished by 

moving the rear sight base in the receiver, as 
necessary, and the elevation is adjusted by the 
height of the front sight blade. In order that the 
above requirements be met, it is advisable to adjust 
the sights as closely as practicable to the place 
where the carbine is shooting. To do this, adjust 
position of rear sight in receiver and height of front 
sight blade.